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Research & Scholarship

Current Research and Scholarly Interests

Our laboratory is dedicated to understanding the pathogenesis of autoimmune diseases, particularly multiple sclerosis. We have developed several new therapies for autoimmunity, including some in Phase 2 clinical trials, as well as one approved drug, natalizumab. We have developed microarray technology for detecting autoantibodies to myelin proteins and lipids. We employ a diverse range of molecular and celluar approaches to trying to understand multiple sclerosis.

Clinical Trials

Biobank For MS And Other Demyelinating DiseasesNot Recruiting

To establish a large, longitudinal collection of high quality samples and data from subjects
with MS, selected other demyelinating diseases (Transverse Myelitis (TM), Neuromyelitis
Optica (NMO) or Devic's, Acute Disseminated Encephalomyelitis (ADEM), and Optic Neuritis
(ON)), and related and unrelated unaffected controls. Samples and data will be available as a
shared resource to scientists researching the causes, sub-types, and biomarkers of MS and
related demyelinating diseases.

Abstract

The alpha7 nicotinic acetylcholine receptor (alpha7nAChR) is central to the anti-inflammatory function of the vagus nerve in a physiological mechanism termed the inflammatory reflex. Studies on the inflammatory reflex have been instrumental for the current development of the field of bioelectronic medicine. An independent investigation of the biological role of alphaB-crystallin (HspB5), the most abundant gene transcript present in active multiple sclerosis lesions in human brains, also led to alpha7nAChR. Induction of experimental autoimmune encephalomyelitis (EAE) in HspB5-/- mice results in greater paralytic signs, increased levels of proinflammatory cytokines, and T-lymphocyte activation relative to wild-type animals. Administration of HspB5 was therapeutic in animal models of multiple sclerosis, retinal and cardiac ischemia, and stroke. Structure-activity studies established that residues 73-92 were as potent as the parent protein, but only when it formed amyloid fibrils. Amyloid fibrils and small heat shock proteins (sHsps) selectively bound alpha7nAChR on peritoneal macrophages (MPhis) and B lymphocytes, converting the MPhis to an immune suppressive phenotype and mobilizing the migration of both cell types from the peritoneum to secondary lymph organs. Here, we review multiple aspects of this work, which may be of interest for developing future therapeutic approaches for multiple sclerosis and other disorders.

Abstract

In gene therapy for Duchenne muscular dystrophy there are two potential immunological obstacles. An individual with Duchenne muscular dystrophy has a genetic mutation in dystrophin, and therefore the wild-type protein is "foreign," and thus potentially immunogenic. The adeno-associated virus serotype-6 (AAV6) vector for delivery of dystrophin is a viral-derived vector with its own inherent immunogenicity. We have developed a technology where an engineered plasmid DNA is delivered to reduce autoimmunity. We have taken this approach into humans, tolerizing to myelin proteins in multiple sclerosis and to proinsulin in type 1 diabetes. Here, we extend this technology to a model of gene therapy to reduce the immunogenicity of the AAV vector and of the wild-type protein product that is missing in the genetic disease. Following gene therapy with systemic administration of recombinant AAV6-microdystrophin to mdx/mTRG2 mice, we demonstrated the development of antibodies targeting dystrophin and AAV6 capsid in control mice. Treatment with the engineered DNA construct encoding microdystrophin markedly reduced antibody responses to dystrophin and to AAV6. Muscle force in the treated mice was also improved compared with control mice. These data highlight the potential benefits of administration of an engineered DNA plasmid encoding the delivered protein to overcome critical barriers in gene therapy to achieve optimal functional gene expression.

Abstract

Objective: We sought to confirm the presence and frequency of B cells and Epstein-Barr virus (EBV) (latent and lytic phase) antigens in archived MS and non-MS brain tissue by immunohistochemistry.Methods: We quantified the type and location of B-cell subsets within active and chronic MS brain lesions in relation to viral antigen expression. The presence of EBV-infected cells was further confirmed by in situ hybridization to detect the EBV RNA transcript, EBV-encoded RNA-1 (EBER-1).Results: We report the presence of EBV latent membrane protein 1 (LMP-1) in 93% of MS and 78% of control brains, with a greater percentage of MS brains containing CD138+ plasma cells and LMP-1-rich populations. Notably, 78% of chronic MS lesions and 33.3% of non-MS brains contained parenchymal CD138+ plasma cells. EBV early lytic protein, EBV immediate-early lytic gene (BZLF1), was also observed in 46% of MS, primarily in association with chronic lesions and 44% of non-MS brain tissue. Furthermore, 85% of MS brains revealed frequent EBER-positive cells, whereas non-MS brains seldom contained EBER-positive cells. EBV infection was detectable, by immunohistochemistry and by in situ hybridization, in both MS and non-MS brains, although latent virus was more prevalent in MS brains, while lytic virus was restricted to chronic MS lesions.Conclusions: Together, our observations suggest an uncharacterized link between the EBV virus life cycle and MS pathogenesis.

Identification of a common immune regulatory pathway induced by small heat shock proteins, amyloid fibrils, and nicotine.Proceedings of the National Academy of Sciences of the United States of AmericaRothbard, J. B., Rothbard, J. J., Soares, L., Fathman, C. G., Steinman, L.2018

Abstract

Although certain dogma portrays amyloid fibrils as drivers of neurodegenerative disease and neuroinflammation, we have found, paradoxically, that amyloid fibrils and small heat shock proteins (sHsps) are therapeutic in experimental autoimmune encephalomyelitis (EAE). They reduce clinical paralysis and induce immunosuppressive pathways, diminishing inflammation. A key question was the identification of the target for these molecules. When sHsps and amyloid fibrils were chemically cross-linked to immune cells, a limited number of proteins were precipitated, including the alpha7 nicotinic acetylcholine receptor (alpha7 NAChR). The alpha7 NAChR is noteworthy among the over 20 known receptors for amyloid fibrils, because it plays a central role in a well-defined immune-suppressive pathway. Competitive binding between amyloid fibrils and alpha-bungarotoxin to peritoneal macrophages (MPhis) confirmed the involvement of alpha7 NAChR. The mechanism of immune suppression was explored, and, similar to nicotine, amyloid fibrils inhibited LPS induction of a common set of inflammatory cytokines while inducing Stat3 signaling and autophagy. Consistent with this, previous studies have established that nicotine, sHsps, and amyloid fibrils all were effective therapeutics in EAE. Interestingly, B lymphocytes were needed for the therapeutic effect. These results suggest that agonists of alpha7 NAChR might have therapeutic benefit for a variety of inflammatory diseases.

Abstract

Rasmussen's encephalitis (RE) is a neuroinflammatory disease that typically affects only one hemisphere of the brain, resulting in severe seizures. Sixty years after the disease was first described, the preferred and best treatment option for RE is grotesque and involves removing a hemisphere of the brain (hemispherectomy); therefore, a better understanding of this seizure disorder may provide additional, less invasive therapeutic options. In this issue of the JCI, Carmant and colleagues have developed an animal model of this focal seizure disorder. The model provides experimental insights into the pathogenesis of RE and potential new treatments for this disease.

Abstract

Neuroinflammation and neurodegeneration may represent two poles of brain pathology. Brain myeloid cells, particularly microglia, play key roles in these conditions. We employed single-cell mass cytometry (CyTOF) to compare myeloid cell populations in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis, the R6/2 model of Huntington's disease (HD) and the mutant superoxide dismutase 1 (mSOD1) model of amyotrophic lateral sclerosis (ALS). We identified three myeloid cell populations exclusive to the CNS and present in each disease model. Blood-derived monocytes comprised five populations and migrated to the brain in EAE, but not in HD and ALS models. Single-cell analysis resolved differences in signaling and cytokine production within similar myeloid populations in EAE compared to HD and ALS models. Moreover, these analyses highlighted alpha5 integrin on myeloid cells as a potential therapeutic target for neuroinflammation. Together, these findings illustrate how neuropathology may differ between inflammatory and degenerative brain disease.

A Journey in Science: The Privilege of Exploring the Brain and the Immune System.Molecular medicine Steinman, L.2016; 22

Abstract

Real innovations in medicine and science are historic and singular; the stories behind each occurrence are precious. At Molecular Medicine we have established the Anthony Cerami Award in Translational Medicine to document and preserve these histories. The monographs recount the seminal events as told in the voice of the original investigators who provided the crucial early insight. These essays capture the essence of discovery, chronicling the birth of ideas that created new fields of research; and launched trajectories that persisted and ultimately influenced how disease is prevented, diagnosed, and treated. In this volume, the Cerami Award Monograph is by Lawrence Steinman, MD, of Stanford University in California. A visionary in the field of neurology, this is the story of Dr. Steinman's scientific journey.

Obeticholic acid, a synthetic bile acid agonist of the farnesoid X receptor, attenuates experimental autoimmune encephalomyelitisPROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICAHo, P. P., Steinman, L.2016; 113 (6): 1600-1605

Abstract

Bile acids are ligands for the nuclear hormone receptor, farnesoid X receptor (FXR). The bile acid-FXR interaction regulates bile acid synthesis, transport, and cholesterol metabolism. Recently, bile acid-FXR regulation has been reported to play an integral role in both hepatic and intestinal inflammation, and in atherosclerosis. In this study, we found that FXR knockout mice had more disease severity in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Obeticholic acid (6α-ethyl-chenodeoxycholic acid, 6-ECDCA), a synthetic FXR agonist, is an orally available drug that is currently in clinical trials for the treatment of inflammatory diseases such as alcoholic hepatitis, nonalcoholic steatohepatitis, and primary biliary cirrhosis. When we treated mice exhibiting established EAE with 6-ECDCA, or the natural FXR ligand chenodeoxycholic acid (CDCA), clinical disease was ameliorated by (i) suppressing lymphocyte activation and proinflammatory cytokine production; (ii) reducing CD4(+) T cells and CD19(+) B cell populations and their expression of negative checkpoint regulators programmed cell death protein 1 (PD1), programmed death-ligand 1 (PD-L1), and B and T lymphocyte attenuator (BTLA); (iii) increasing CD8(+) T cells and PD1, PDl-1, and BTLA expression; and (iv) reducing VLA-4 expression in both the T- and B-cell populations. Moreover, adoptive transfer of 6-ECDCA- or CDCA-treated donor cells failed to transfer disease in naive recipients. Thus, we show that FXR functions as a negative regulator in neuroinflammation and we highlight that FXR agonists represent a potential previously unidentified therapy for MS.

Abstract

Amyloid fibrils composed of peptides as short as six amino acids are therapeutic in experimental autoimmune encephalomyelitis (EAE), reducing paralysis and inflammation, while inducing several pathways of immune suppression. Intraperitoneal injection of fibrils selectively activates B-1a lymphocytes and two populations of resident macrophages (MΦs), increasing IL-10 production, and triggering their exodus from the peritoneum. The importance of IL-10-producing B-1a cells in this effective therapy was established in loss-of-function experiments where neither B-cell-deficient (μMT) nor IL10(-/-) mice with EAE responded to the fibrils. In gain-of-function experiments, B-1a cells, adoptively transferred to μMT mice with EAE, restored their therapeutic efficacy when Amylin 28-33 was administered. Stimulation of adoptively transferred bioluminescent MΦs and B-1a cells by amyloid fibrils resulted in rapid (within 60 min of injection) trafficking of both cell types to draining lymph nodes. Analysis of gene expression indicated that the fibrils activated the CD40/B-cell receptor pathway in B-1a cells and induced a set of immune-suppressive cell-surface proteins, including BTLA, IRF4, and Siglec G. Collectively, these data indicate that the fibrils activate B-1a cells and F4/80(+) MΦs, resulting in their migration to the lymph nodes, where IL-10 and cell-surface receptors associated with immune-suppression limit antigen presentation and T-cell activation. These mechanisms culminate in reduction of paralytic signs of EAE.

Abstract

The sleep disorder narcolepsy is linked to the HLA-DQB1*0602 haplotype and dysregulation of the hypocretin ligand-hypocretin receptor pathway. Narcolepsy was associated with Pandemrix vaccination (an adjuvanted, influenza pandemic vaccine) and also with infection by influenza virus during the 2009 A(H1N1) influenza pandemic. In contrast, very few cases were reported after Focetria vaccination (a differently manufactured adjuvanted influenza pandemic vaccine). We hypothesized that differences between these vaccines (which are derived from inactivated influenza viral proteins) explain the association of narcolepsy with Pandemrix-vaccinated subjects. A mimic peptide was identified from a surface-exposed region of influenza nucleoprotein A that shared protein residues in common with a fragment of the first extracellular domain of hypocretin receptor 2. A significant proportion of sera from HLA-DQB1*0602 haplotype-positive narcoleptic Finnish patients with a history of Pandemrix vaccination (vaccine-associated narcolepsy) contained antibodies to hypocretin receptor 2 compared to sera from nonnarcoleptic individuals with either 2009 A(H1N1) pandemic influenza infection or history of Focetria vaccination. Antibodies from vaccine-associated narcolepsy sera cross-reacted with both influenza nucleoprotein and hypocretin receptor 2, which was demonstrated by competitive binding using 21-mer peptide (containing the identified nucleoprotein mimic) and 55-mer recombinant peptide (first extracellular domain of hypocretin receptor 2) on cell lines expressing human hypocretin receptor 2. Mass spectrometry indicated that relative to Pandemrix, Focetria contained 72.7% less influenza nucleoprotein. In accord, no durable antibody responses to nucleoprotein were detected in sera from Focetria-vaccinated nonnarcoleptic subjects. Thus, differences in vaccine nucleoprotein content and respective immune response may explain the narcolepsy association with Pandemrix.

Abstract

The brain under immunological attack does not surrender quietly. Investigation of brain lesions in multiple sclerosis (MS) reveals a coordinated molecular response involving various proteins and small molecules ranging from heat shock proteins to small lipids, neurotransmitters, and even gases, which provide protection and foster repair. Reduction of inflammation serves as a necessary prerequisite for effective recovery and regeneration. Remarkably, many lesion-resident molecules activate pathways leading to both suppression of inflammation and promotion of repair mechanisms. These guardian molecules and their corresponding physiologic pathways could potentially be exploited to silence inflammation and repair the injured and degenerating brain and spinal cord in both relapsing-remitting and progressive forms of MS and may be beneficial in other neurologic and psychiatric conditions.

Abstract

Amyloid fibrils composed of peptides as short as six amino acids are effective therapeutics for experimental autoimmune encephalomyelitis (EAE). Immunosuppression arises from at least two pathways: (1) expression of type 1 IFN by pDCs, which were induced by neutrophil extracellular traps arising from the endocytosis of the fibrils; and (2) the reduced expression of IFN-γ, TNF, and IL-6. The two independent pathways stimulated by the fibrils can act in concert to be immunosuppressive in Th1 indications, or in opposition, resulting in inflammation when Th17 T lymphocytes are predominant. The generation of type 1 IFN can be minimized by using polar, nonionizable, amyloidogenic peptides, which are effective in both Th1 and Th17 polarized EAE.

Abstract

Eighty percent of individuals with multiple sclerosis (MS) initially develop a clinical pattern with periodic relapses followed by remissions, called relapsing-remitting MS (RRMS). This period of fluctuating disease may last for a decade or more. Clinical relapses reflect acute inflammation in the central nervous system (CNS), composed of the brain and spinal cord. Often, different anatomic areas in the CNS are involved each time a relapse occurs, resulting in varied clinical manifestations in each instance. Relapses are nearly always followed by some degree of remission, though recovery to baseline status before the flare is often incomplete. There are nine approved drugs for treatment of RRMS. The most potent drug for inhibiting relapses, the humanized anti-α4 integrin antibody known as Natalizumab, blocks homing of mononuclear cells to the CNS. The mechanisms of action of the approved drugs for RRMS provide a strong foundation for understanding the pathobiology of the relapse. Despite substantial progress in controlling relapses with the current armamentarium of medications, there is much to learn and ever more effective and safe therapies to develop.

Abstract

In type 1 diabetes (T1D), there is an intense inflammatory response that destroys the β cells in the pancreatic islets of Langerhans, the site where insulin is produced and released. A therapy for T1D that targets the specific autoimmune response in this disease while leaving the remainder of the immune system intact, has long been sought. Proinsulin is a major target of the adaptive immune response in T1D. We hypothesized that an engineered DNA plasmid encoding proinsulin (BHT-3021) would preserve β cell function in T1D patients through reduction of insulin-specific CD8(+) T cells. We studied 80 subjects over 18 years of age who were diagnosed with T1D within the past 5 years. Subjects were randomized 2:1 to receive intramuscular injections of BHT-3021 or BHT-placebo, weekly for 12 weeks, and then monitored for safety and immune responses in a blinded fashion. Four dose levels of BHT-3021 were evaluated: 0.3, 1.0, 3.0, and 6.0 mg. C-peptide was used both as an exploratory efficacy measure and as a safety measure. Islet-specific CD8(+) T cell frequencies were assessed with multimers of monomeric human leukocyte antigen class I molecules loaded with peptides from pancreatic and unrelated antigens. No serious adverse events related to BHT-3021 were observed. C-peptide levels improved relative to placebo at all doses, at 1 mg at the 15-week time point (+19.5% BHT-3021 versus -8.8% BHT-placebo, P < 0.026). Proinsulin-reactive CD8(+) T cells, but not T cells against unrelated islet or foreign molecules, declined in the BHT-3021 arm (P < 0.006). No significant changes were noted in interferon-γ, interleukin-4 (IL-4), or IL-10 production in CD4 T cells. Thus, we demonstrate that a plasmid encoding proinsulin reduces the frequency of CD8(+) T cells reactive to proinsulin while preserving C-peptide over the course of dosing.

Abstract

Oligodendrocytes-the myelin-forming cells of the central nervous system-can be regenerated during adulthood. In adults, new oligodendrocytes originate from oligodendrocyte progenitor cells (OPCs), but also from neural stem cells (NSCs). Although several factors supporting oligodendrocyte production have been characterized, the mechanisms underlying the generation of adult oligodendrocytes are largely unknown. Here we show that genetic inactivation of SIRT1, a protein deacetylase implicated in energy metabolism, increases the production of new OPCs in the adult mouse brain, in part by acting in NSCs. New OPCs produced following SIRT1 inactivation differentiate normally, generating fully myelinating oligodendrocytes. Remarkably, SIRT1 inactivation ameliorates remyelination and delays paralysis in mouse models of demyelinating injuries. SIRT1 inactivation leads to the upregulation of genes involved in cell metabolism and growth factor signalling, in particular PDGF receptor α (PDGFRα). Oligodendrocyte expansion following SIRT1 inactivation is mediated at least in part by AKT and p38 MAPK-signalling molecules downstream of PDGFRα. The identification of drug-targetable enzymes that regulate oligodendrocyte regeneration in adults could facilitate the development of therapies for demyelinating injuries and diseases, such as multiple sclerosis.

Abstract

The amyloid-forming proteins tau, αB crystallin, and amyloid P protein are all found in lesions of multiple sclerosis (MS). Our previous work established that amyloidogenic peptides from the small heat shock protein αB crystallin (HspB5) and from amyloid β fibrils, characteristic of Alzheimer's disease, were therapeutic in experimental autoimmune encephalomyelitis (EAE), reflecting aspects of the pathology of MS. To understand the molecular basis for the therapeutic effect, we showed a set of amyloidogenic peptides composed of six amino acids, including those from tau, amyloid β A4, major prion protein (PrP), HspB5, amylin, serum amyloid P, and insulin B chain, to be anti-inflammatory and capable of reducing serological levels of interleukin-6 and attenuating paralysis in EAE. The chaperone function of the fibrils correlates with the therapeutic outcome. Fibrils composed of tau 623-628 precipitated 49 plasma proteins, including apolipoprotein B-100, clusterin, transthyretin, and complement C3, supporting the hypothesis that the fibrils are active biological agents. Amyloid fibrils thus may provide benefit in MS and other neuroinflammatory disorders.

Abstract

Most scientists agree that comprehension of primary scientific papers and communication of scientific concepts are two of the most important skills that we can teach, but few undergraduate biology courses make these explicit course goals. We designed an undergraduate neuroimmunology course that uses a writing-intensive format. Using a mixture of primary literature, writing assignments directed toward a layperson and scientist audience, and in-class discussions, we aimed to improve the ability of students to 1) comprehend primary scientific papers, 2) communicate science to a scientific audience, and 3) communicate science to a layperson audience. We offered the course for three consecutive years and evaluated its impact on student perception and confidence using a combination of pre- and postcourse survey questions and coded open-ended responses. Students showed gains in both the perception of their understanding of primary scientific papers and of their abilities to communicate science to scientific and layperson audiences. These results indicate that this unique format can teach both communication skills and basic science to undergraduate biology students. We urge others to adopt a similar format for undergraduate biology courses to teach process skills in addition to content, thus broadening and strengthening the impact of undergraduate courses.

Abstract

When considering the hierarchical organization of pathological signaling cascades in immunological disorders of the brain, certain cytokines might be considered pinnacles of pathophysiological importance, with their presence determining the appearance or the course of a particular disease. Interleukin-1 (IL-1), IL-6, IL-17, and tumor necrosis factor are critical for the pathogenesis of inflammation in specific brain disorders. Targeting these cytokines or their receptors can alter the course of several neurological diseases, but the effects may be beneficial or harmful.

Abstract

Four questions were posed about multiple sclerosis (MS) at the 2011 Charcot Lecture, Oct. 22, 2011. 1. The Male/Female Disparity: Why are women developing MS so much more frequently than men? 2. Neuronal and Glial Protection: Are there guardian molecules that protect the nervous system in MS? 3. Predictive Medicine: With all the approved drugs, how can we rationally decide which one to use? 4. The Precise Scalpel vs. the Big Hammer for Therapy: Is antigen-specific therapy for demyelinating disease possible? To emphasize how our views on the pathogenesis and treatment of MS are evolving, and given the location of the talk in Amsterdam, Piet Mondrian's progressive interpretations of trees serve as a heuristic.

Science Communication to the General Public: Why We Need to Teach Undergraduate and Graduate Students this Skill as Part of Their Formal Scientific Training.Journal of undergraduate neuroscience education : JUNE : a publication of FUN, Faculty for Undergraduate NeuroscienceBrownell, S. E., Price, J. V., Steinman, L.2013; 12 (1): E6-E10

Abstract

Multiple sclerosis (MS) is the major inflammatory demyelinating disease of the central nervous system. There is strong evidence that an immune response in the brain is a critical component of the disease. In 1992, in a collaboration between academia and biotechnology, my colleagues and I showed that α4 integrin was the critical molecule involved in the homing of immune cells into the inflamed brain. Was it sheer luck that these results led to the development of a drug for MS?

Abstract

To determine whether the therapeutic activity of αB crystallin, small heat shock protein B5 (HspB5), was shared with other human sHsps, a set of seven human family members, a mutant of HspB5 G120 known to exhibit reduced chaperone activity, and a mycobacterial sHsp were expressed and purified from bacteria. Each of the recombinant proteins was shown to be a functional chaperone, capable of inhibiting aggregation of denatured insulin with varying efficiency. When injected into mice at the peak of disease, they were all effective in reducing the paralysis in experimental autoimmune encephalomyelitis. Additional structure activity correlations between chaperone activity and therapeutic function were established when linear regions within HspB5 were examined. A single region, corresponding to residues 73-92 of HspB5, forms amyloid fibrils, exhibited chaperone activity, and was an effective therapeutic for encephalomyelitis. The linkage of the three activities was further established by demonstrating individual substitutions of critical hydrophobic amino acids in the peptide resulted in the loss of all of the functions.

Abstract

β-Amyloid 42 (Aβ42) and β-amyloid 40 (Aβ40), major components of senile plaque deposits in Alzheimer's disease, are considered neurotoxic and proinflammatory. In multiple sclerosis, Aβ42 is up-regulated in brain lesions and damaged axons. We found, unexpectedly, that treatment with either Aβ42 or Aβ40 peptides reduced motor paralysis and brain inflammation in four different models of experimental autoimmune encephalomyelitis (EAE) with attenuation of motor paralysis, reduction of inflammatory lesions in the central nervous system (CNS), and suppression of lymphocyte activation. Aβ42 and Aβ40 treatments were effective in reducing ongoing paralysis induced with adoptive transfer of either autoreactive T helper 1 (T(H)1) or T(H)17 cells. High-dimensional 14-parameter flow cytometry of peripheral immune cell populations after in vivo Aβ42 and Aβ40 treatment revealed substantial modulations in the percentage of lymphoid and myeloid subsets during EAE. Major proinflammatory cytokines and chemokines were reduced in the blood after Aβ peptide treatment. Protection conferred by Aβ treatment did not require its delivery to the brain: Adoptive transfer with lymphocytes from donors treated with Aβ42 attenuated EAE in wild-type recipient mice, and Aβ deposition in the brain was not detected in treated EAE mice by immunohistochemical analysis. In contrast to the improvement in EAE with Aβ treatment, EAE was worse in mice with genetic deletion of the amyloid precursor protein. Therefore, in the absence of Aβ, there is exacerbated clinical EAE disease progression. Because Aβ42 and Aβ40 ameliorate experimental autoimmune inflammation targeting the CNS, we might now consider its potential anti-inflammatory role in other neuropathological conditions.

Abstract

Comparison of transcriptomic and proteomic data from pathologically similar multiple sclerosis (MS) lesions reveals down-regulation of CD47 at the messenger RNA level and low abundance at the protein level. Immunohistochemical studies demonstrate that CD47 is expressed in normal myelin and in foamy macrophages and reactive astrocytes within active MS lesions. We demonstrate that CD47(-/-) mice are refractory to experimental autoimmune encephalomyelitis (EAE), primarily as the result of failure of immune cell activation after immunization with myelin antigen. In contrast, blocking with a monoclonal antibody against CD47 in mice at the peak of paralysis worsens EAE severity and enhances immune activation in the peripheral immune system. In vitro assays demonstrate that blocking CD47 also promotes phagocytosis of myelin and that this effect is dependent on signal regulatory protein α (SIRP-α). Immune regulation and phagocytosis are mechanisms for CD47 signaling in autoimmune neuroinflammation. Depending on the cell type, location, and disease stage, CD47 has Janus-like roles, with opposing effects on EAE pathogenesis.

Abstract

Women develop certain autoimmune diseases more often than men. It has been hypothesized that this may relate to the development of more robust T-helper (Th)1 responses in women. To test whether women exhibit a Th1 bias, we isolated naïve cluster of differentiation (CD)4(+) T cells from peripheral blood of healthy women and men and measured the proliferation and cytokine production by these cells in response to submaximal amounts of anti-CD3 and anti-CD28. We observed that CD4(+) T cells from women produced higher levels of IFNγ as well as tended to proliferate more than male CD4(+) T cells. Intriguingly, male CD4(+) T cells instead had a predilection toward IL-17A production. This sex dichotomy in Th cytokine production was found to be even more striking in the Swiss/Jackson Laboratory (SJL) mouse. Studies in mice and humans indicated that the sexual dimorphism in Th1 and Th17 cytokine production was dependent on the androgen status and the T-cell expression of peroxisome proliferator activated receptor (PPAR)α and PPARγ. Androgens increased PPARα and decreased PPARγ expression by human CD4(+) T cells. PPARα siRNA-mediated knockdown had the effect of increasing IFNγ by male CD4(+) T cells, while transfection of CD4(+) T cells with PPARγ siRNAs increased IL-17A production uniquely by female T cells. Together, our observations indicate that human T cells exhibit a sex difference in the production of IFNγ and IL-17A that may be driven by expressions of PPARα and PPARγ.

Abstract

Women develop certain autoimmune diseases more often than men. It has been hypothesized that this may relate to the development of more robust T-helper (Th)1 responses in women. To test whether women exhibit a Th1 bias, we isolated naïve cluster of differentiation (CD)4(+) T cells from peripheral blood of healthy women and men and measured the proliferation and cytokine production by these cells in response to submaximal amounts of anti-CD3 and anti-CD28. We observed that CD4(+) T cells from women produced higher levels of IFNγ as well as tended to proliferate more than male CD4(+) T cells. Intriguingly, male CD4(+) T cells instead had a predilection toward IL-17A production. This sex dichotomy in Th cytokine production was found to be even more striking in the Swiss/Jackson Laboratory (SJL) mouse. Studies in mice and humans indicated that the sexual dimorphism in Th1 and Th17 cytokine production was dependent on the androgen status and the T-cell expression of peroxisome proliferator activated receptor (PPAR)α and PPARγ. Androgens increased PPARα and decreased PPARγ expression by human CD4(+) T cells. PPARα siRNA-mediated knockdown had the effect of increasing IFNγ by male CD4(+) T cells, while transfection of CD4(+) T cells with PPARγ siRNAs increased IL-17A production uniquely by female T cells. Together, our observations indicate that human T cells exhibit a sex difference in the production of IFNγ and IL-17A that may be driven by expressions of PPARα and PPARγ.

Abstract

Lipids constitute 70% of the myelin sheath, and autoantibodies against lipids may contribute to the demyelination that characterizes multiple sclerosis (MS). We used lipid antigen microarrays and lipid mass spectrometry to identify bona fide lipid targets of the autoimmune response in MS brain, and an animal model of MS to explore the role of the identified lipids in autoimmune demyelination. We found that autoantibodies in MS target a phosphate group in phosphatidylserine and oxidized phosphatidylcholine derivatives. Administration of these lipids ameliorated experimental autoimmune encephalomyelitis by suppressing activation and inducing apoptosis of autoreactive T cells, effects mediated by the lipids' saturated fatty acid side chains. Thus, phospholipids represent a natural anti-inflammatory class of compounds that have potential as therapeutics for MS.

Abstract

The pathology of neuromyelitis optica (NMO), in contrast to multiple sclerosis, comprises granulocyte infiltrates along extensive lengths of spinal cord, as well as optic nerve. Furthermore, IFN-β treatment worsens NMO. We recently found that experimental autoimmune encephalomyelitis (EAE) induced with Th17 cells is exacerbated by IFN-β, in contrast to disease induced with Th1 where treatment attenuated symptoms.This study demonstrates the similarities between NMO and Th17 EAE and how neutrophils mediate pathology in Th17 disease.Levels of blood biomarkers in NMO were assessed by Luminex and ELISA. Effects of IFN-β on neutrophils were assessed by culture assays and immunofluorescence. EAE was induced by transfer of myelin-specific Th1 or Th17 cells and treated with Sivelestat sodium hydrate, a neutrophil elastase inhibitor.We show Th17 cytokines, granulocyte chemokines, type 1 interferon and neutrophil elastase are elevated in patients with definitive NMO. In culture, we find that IFN-β stimulates neutrophils to release neutrophil elastase. In Th17 EAE, we demonstrate neutrophilic infiltration in the optic nerve and spinal cord which was not present in Th1 EAE. Blockade of neutrophil elastase with Sivelestat had efficacy in Th17 EAE but not Th1 EAE.The similarities between Th17 EAE and NMO indicate that this model represents several aspects of NMO. Neutrophils are critical in the pathologies of both Th17-EAE and NMO, and therefore blockade of neutrophil elastase is a promising target in treating NMO.

Abstract

The therapeutic benefit of the small heat shock protein αB-crystallin (HspB5) in animal models of multiple sclerosis and ischemia is proposed to arise from its increased capacity to bind proinflammatory proteins at the elevated temperatures within inflammatory foci. By mass spectral analysis, a common set of ∼70 ligands was precipitated by HspB5 from plasma from patients with multiple sclerosis, rheumatoid arthritis, and amyloidosis and mice with experimental allergic encephalomyelitis. These proteins were distinguished from other precipitated molecules because they were enriched in the precipitate as compared with their plasma concentrations, and they exhibited temperature-dependent binding. More than half of these ligands were acute phase proteins or members of the complement or coagulation cascades. Consistent with this proposal, plasma levels of HspB5 were increased in patients with multiple sclerosis as compared with normal individuals. The combination of the thermal sensitivity of the HspB5 combined with the high local concentration of these ligands at the site of inflammation is proposed to explain the paradox of how a protein believed to exhibit nonspecific binding can bind with some relative apparent selectivity to proinflammatory proteins and thereby modulate inflammation.

Abstract

Tissue plasminogen activator is the only treatment option for stroke victims; however, it has to be administered within 4.5 h after symptom onset, making its use very limited. This report describes a unique target for effective treatment of stroke, even 12 h after onset, by the administration of αB-crystallin (Cryab), an endogenous immunomodulatory neuroprotectant. In Cryab(-/-) mice, there was increased lesion size and diminished neurologic function after stroke compared with wild-type mice. Increased plasma Cryab was detected after experimental stroke in mice and after stroke in human patients. Administration of Cryab even 12 h after experimental stroke reduced both stroke volume and inflammatory cytokines associated with stroke pathology. Cryab is an endogenous anti-inflammatory and neuroprotectant molecule produced after stroke, whose beneficial properties can be augmented when administered therapeutically after stroke.

Abstract

Anterior ischemic optic neuropathy (AION) is an important cause of acute vision loss in adults, and there is no effective treatment. We studied early changes following experimental AION and tested the benefit of a potential treatment.Materials andWe induced experimental AION in adult mice and tested the effects of short-term (daily for 3 days) and long-term (every other day for 3 weeks) αB-crystallin (αBC) treatment using histological and serial intracranial flash visual evoked potential recordings.One day after experimental AION, there was swelling at the optic nerve (ON) head and increased expression of αBC, a small heat shock protein important in ischemia and inflammation. This upregulation coincided with microglial and astrocytic activation. Our hypothesis was that αBC may be part of the endogenous protective mechanism against injury, thus we tested the effects of αBC on experimental AION. Daily intraveneous or intravitreal αBC injections did not improve visual evoked potential amplitude or latency at days 1-2. However, αBC treatment decreased swelling and dampened the microglial and astrocytic activation on day 3. Longer treatment with intravenous αBC led to acceleration of visual evoked potential latency over 3 weeks, without improving amplitude. This latency acceleration did not correlate with increased retinal ganglion cell survival but did correlate with complete rescue of the ON oligodendrocytes, which are important for myelination.We identified αBC as an early marker following experimental AION. Treatment with αBC enhanced this endogenous, post-ischemic response by decreasing microglial activation and promoting ON oligodendrocyte survival.

Abstract

Interferon (IFN)-β is the treatment most often prescribed for relapsing-remitting multiple sclerosis (RRMS). 30-50% of MS patients, however, do not respond to IFN-β. In some cases, IFN-β exacerbates MS, and it consistently worsens neuromyelitis optica (NMO). To eliminate unnecessary treatment for patients who are non-responsive to IFN-β, and to avoid possible harm, researchers are identifying biomarkers that predict treatment outcome before treatment is initiated. These biomarkers reveal insights into the mechanisms of disease. Recent discoveries on human samples from patients with RRMS, NMO, psoriasis, rheumatoid arthritis, systemic lupus erythematosus and ulcerative colitis, indicate that IFN-β is ineffective and might worsen clinical status in diverse diseases when a Th17 immune response is prominent.

Abstract

For 15 y, α B-crystallin (heat shock protein [Hsp] B5) has been labeled an autoantigen in multiple sclerosis (MS) based on humoral and cellular responses found in humans and animal models. However, there have been several scientific inconsistencies with this assignment, ranging from studies demonstrating small differences in anticrystallin responses between patients and healthy individuals to the inability of crystallin-specific T cells to induce symptoms of experimental allergic encephalomyelitis in animal models. Experiments in this article demonstrate that the putative anti-HspB5 Abs from 23 MS patients cross-react with 7 other members of the human small Hsp family and were equally present in normal plasma. Biolayer interferometry demonstrates that the binding was temperature dependent, and that the calculated K(a) increased as the concentration of the sHsp decreased. These two patterns are characteristic of multiple binding sites with varying affinities, the composition of which changes with temperature, supporting the hypothesis that HspB5 bound the Ab and not the reverse. HspB5 also precipitated Ig heavy and L chains from sera from patients with MS. These results establish that small Hsps bind Igs with high affinity and refute much of the serological data used to assign α B-crystallin as an autoantigen.

Modulation of postoperative cognitive decline via blockade of inflammatory cytokines outside the brainPROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICASteinman, L.2010; 107 (48): 20595-20596

Abstract

Peroxisome proliferator-activated receptors (PPARs; PPAR-alpha, PPAR-delta, and PPAR-gamma) comprise a family of nuclear receptors that sense fatty acid levels and translate this information into altered gene transcription. Previously, it was reported that treatment of mice with a synthetic ligand activator of PPAR-delta, GW0742, ameliorates experimental autoimmune encephalomyelitis (EAE), indicating a possible role for this nuclear receptor in the control of central nervous system (CNS) autoimmune inflammation. We show that mice deficient in PPAR-delta (PPAR-delta(-/-)) develop a severe inflammatory response during EAE characterized by a striking accumulation of IFN-gamma(+)IL-17A(-) and IFN-gamma(+)IL-17A(+) CD4(+) cells in the spinal cord. The preferential expansion of these T helper subsets in the CNS of PPAR-delta(-/-) mice occurred as a result of a constellation of immune system aberrations that included higher CD4(+) cell proliferation, cytokine production, and T-bet expression and enhanced expression of IL-12 family cytokines by myeloid cells. We also show that the effect of PPAR-delta in inhibiting the production of IFN-gamma and IL-12 family cytokines is ligand dependent and is observed in both mouse and human immune cells. Collectively, these findings suggest that PPAR-delta serves as an important molecular brake for the control of autoimmune inflammation.

Abstract

DNA-based vaccines to induce antigen-specific inhibition of immune responses in human autoimmune diseases represent the inverse of what Jenner intended when he invented vaccination. Jenner's vaccine induced antigen-specific immunity to small pox. DNA vaccines for autoimmunity have been developed in preclinical settings, and now tested in human trials. The first two clinical trials, one in relapsing remitting multiple sclerosis, and the other in type 1 diabetes indicate that specific inhibition of antigen-specific antibody and T-cell responses is attainable in humans. Further development of this approach is ongoing. This new version of immunization termed 'inverse vaccination' when applied to autoimmune diseases, may allow targeted reduction of unwanted antibody and T-cell responses to autoantigens, while leaving the remainder of the immune system intact. The method of specifically reducing a pathological adaptive autoimmune response is termed inverse vaccination.

Abstract

Interferon-beta (IFN-beta) is the major treatment for multiple sclerosis. However, this treatment is not always effective. Here we have found congruence in outcome between responses to IFN-beta in experimental autoimmune encephalomyelitis (EAE) and relapsing-remitting multiple sclerosis (RRMS). IFN-beta was effective in reducing EAE symptoms induced by T helper type 1 (T(H)1) cells but exacerbated disease induced by T(H)17 cells. Effective treatment in T(H)1-induced EAE correlated with increased interleukin-10 (IL-10) production by splenocytes. In T(H)17-induced disease, the amount of IL-10 was unaltered by treatment, although, unexpectedly, IFN-beta treatment still reduced IL-17 production without benefit. Both inhibition of IL-17 and induction of IL-10 depended on IFN-gamma. In the absence of IFN-gamma signaling, IFN-beta therapy was ineffective in EAE. In RRMS patients, IFN-beta nonresponders had higher IL-17F concentrations in serum compared to responders. Nonresponders had worse disease with more steroid usage and more relapses than did responders. Hence, IFN-beta is proinflammatory in T(H)17-induced EAE. Moreover, a high IL-17F concentration in the serum of people with RRMS is associated with nonresponsiveness to therapy with IFN-beta.

Inhibitory role for GABA in autoimmune inflammationPROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICABhat, R., Axtell, R., Mitra, A., Miranda, M., Lock, C., Tsien, R. W., Steinman, L.2010; 107 (6): 2580-2585

Abstract

GABA, the principal inhibitory neurotransmitter in the adult brain, has a parallel inhibitory role in the immune system. We demonstrate that immune cells synthesize GABA and have the machinery for GABA catabolism. Antigen-presenting cells (APCs) express functional GABA receptors and respond electrophysiologically to GABA. Thus, the immune system harbors all of the necessary constituents for GABA signaling, and GABA itself may function as a paracrine or autocrine factor. These observations led us to ask further whether manipulation of the GABA pathway influences an animal model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE). Increasing GABAergic activity ameliorates ongoing paralysis in EAE via inhibition of inflammation. GABAergic agents act directly on APCs, decreasing MAPK signals and diminishing subsequent adaptive inflammatory responses to myelin proteins.

Abstract

The immune system has two major components, an innate arm and an adaptive arm. Certain autoimmune diseases of the brain represent examples of disorders where one of these constituents plays a major role. Some rare autoimmune diseases involve activation of the innate arm and include chronic infantile neurologic, cutaneous, articular (CINCA) syndrome. In contrast, adaptive immunity is prominent in multiple sclerosis, neuromyelitis optica, and the paraneoplastic syndromes where highly specific T cell responses and antibodies mediate these diseases. Studies of autoimmune brain disorders have aided in the elucidation of distinct neuronal roles played by key molecules already well known to immunologists (e.g., complement and components of the major histocompatibility complex). In parallel, molecules known to neurobiology and sensory physiology, including toll-like receptors, gamma amino butyric acid and the lens protein alpha B crystallin, have intriguing and distinct functions in the immune system, where they modulate autoimmunity directed to the brain.

Abstract

The renin-angiotensin-aldosterone system (RAAS) is a major regulator of blood pressure. The octapeptide angiotensin II (AII) is proteolytically processed from the decapeptide AI by angiotensin-converting enzyme (ACE), and then acts via angiotensin type 1 and type 2 receptors (AT1R and AT2R). Inhibitors of ACE and antagonists of the AT1R are used in the treatment of hypertension, myocardial infarction, and stroke. We now show that the RAAS also plays a major role in autoimmunity, exemplified by multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Using proteomics, we observed that RAAS is up-regulated in brain lesions of MS. AT1R was induced in myelin-specific CD4+ T cells and monocytes during autoimmune neuroinflammation. Blocking AII production with ACE inhibitors or inhibiting AII signaling with AT1R blockers suppressed autoreactive TH1 and TH17 cells and promoted antigen-specific CD4+FoxP3+ regulatory T cells (Treg cells) with inhibition of the canonical NF-kappaB1 transcription factor complex and activation of the alternative NF-kappaB2 pathway. Treatment with ACE inhibitors induces abundant CD4+FoxP3+ T cells with sufficient potency to reverse paralytic EAE. Modulation of the RAAS with inexpensive, safe pharmaceuticals used by millions worldwide is an attractive therapeutic strategy for application to human autoimmune diseases.

Abstract

Two thirds of patients with multiple sclerosis have the relapsing-remitting form, which often progresses to more debilitating disease. Striking clinical recovery, termed remission, often follows these periodic neurological defects, termed relapses. Recent work has revealed the role of three key molecules in relapse and remission: alpha4beta1 integrin (also known as VLA4) is an adhesion molecule that mediates T cell migration from the blood into the brain; osteopontin binds to alpha4beta1 integrin, stimulating the production of pro-inflammatory cytokines and inhibiting apoptosis; and alphaB crystallin inhibits inflammation in the brain. This Review discusses how this molecular trio interacts to initiate relapses (in the case of osteopontin and alpha4beta1 integrin) and then to terminate them as remissions in multiple sclerosis (in the case of alphaB crystallin).

Abstract

Insulin is a major target for the autoimmune-mediated destruction of pancreatic beta cells during the pathogenesis of type I diabetes. A plasmid DNA vaccine encoding mouse proinsulin II reduced the incidence of diabetes in a mouse model of type I diabetes when administered to hyperglycemic (therapeutic mode) or normoglycemic (prophylactic mode) NOD mice. Therapeutic administration of proinsulin DNA was accompanied by a rapid decrease in the number of insulin-specific IFN-gamma-producing T cells, whereas prophylactic treatment was accompanied by enhanced IFN-gamma-secreting cells and a decrease in insulin autoantibodies. Adoptive transfer experiments demonstrated that the protection was not mediated by induction of CD25(+)/CD4(+) T regulatory cells. The efficacy of the DNA vaccine was enhanced by increasing the level of expression of the encoded Ag, more frequent dosing, increasing dose level, and localization of the protein product to the intracellular compartment. The efficacy data presented in this study demonstrate that Ag-specific plasmid DNA therapy is a viable strategy for preventing progression of type I diabetes and defines critical parameters of the dosing regime that influences tolerance induction.

Abstract

The three most prevalent human disorders of the CNS in which immunity and inflammation are likely to have vital roles (excluding infection of the CNS) are fever, multiple sclerosis (MS), and Alzheimer disease (AD). As reviewed here, cytokines are critical in the induction of fever, the pathogenesis of MS, and the pathobiology of AD. Indeed, antibodies targeting cytokines have been used as a therapy for individuals with unusual and persistent febrile reactions not responsive to common antipyretics, while a recombinant cytokine is the most popular treatment for the relapsing-remitting form of MS. Although cytokine-modulating therapies are not currently in clinical use for the treatment of AD, cytokines can ameliorate disease pathology in certain experimental models of AD, suggesting a potential for future therapeutic opportunities.

A rush to judgment on Th17JOURNAL OF EXPERIMENTAL MEDICINESteinman, L.2008; 205 (7): 1517-1522

Abstract

Some immunologists have characterized T helper (Th)17 T cells as the master mediators of tissue damage in a variety of pathological conditions. New data now demonstrate that Th1 and Th17 T cells are independently capable of inducing disease in two established models of autoimmunity. Thus, the role of Th17 cytokines as the central mediators of pathological tissue damage seems to require clarification.

Abstract

To evaluate the efficacy and safety of BHT-3009 in relapsing-remitting multiple sclerosis (MS) and to confirm that BHT-3009 causes immune tolerance.BHT-3009 is a tolerizing DNA vaccine for MS, encoding full-length human myelin basic protein. Relapsing-remitting MS patients were randomized 1:1:1 into three groups: placebo, 0.5 mg BHT-3009, or 1.5 mg BHT-3009, given intramuscularly at weeks 0, 2, 4, and every 4 weeks thereafter until week 44. The primary end point was the 4-week rate of occurrence of new gadolinium-enhancing lesions on brain magnetic resonance images from weeks 28 to 48. Protein microarrays were used to measure levels of anti-myelin autoantibodies.Compared with placebo, in the 267 patient analysis population the median 4-week rate of new enhancing lesions during weeks 28 to 48 was 50% lower with 0.5 mg BHT-3009 (p = 0.07) and during weeks 8 to 48 was 61% lower with 0.5 mg BHT-3009 (p = 0.05). The mean volume of enhancing lesions at week 48 was 51% lower on 0.5 mg BHT-3009 compared with placebo (p = 0.02). No significant improvement in magnetic resonance imaging lesion parameters was observed with 1.5 mg BHT-3009. Dramatic reductions in 23 myelin-specific autoantibodies in the 0.5 mg BHT-3009 arm were observed, but not with placebo or 1.5 mg BHT-3009.In relapsing-remitting MS patients, treatment with the lower dose (0.5 mg) of BHT-3009 for 44 weeks nearly attained the primary end point for reduction of the rate of new enhancing magnetic resonance imaging lesions (p = 0.07) and achieved several secondary end points including a reduction of the rate of enhancing magnetic resonance imaging lesions from weeks 8 to 48 (p = 0.05). Immunological data in a preselected subgroup of patients also indicated that treatment with 0.5 mg induced antigen-specific immune tolerance. The greater dose was ineffective.

Abstract

To assess safety and immune modulation by BHT-3009, a tolerizing DNA vaccine encoding full-length human myelin basic protein, in patients with multiple sclerosis (MS).The study was a randomized, double-blind, placebo-controlled trial. Subjects receiving placebo were crossed over into an active arm after treatment unblinding.The trial was conducted at 4 academic institutions within North America. Patients Thirty patients with relapsing-remitting or secondary progressive MS who were not taking any other disease-modifying drugs were enrolled in the trial. Further, the patients were required to have either 1 to 5 gadolinium-enhancing lesions on screening brain magnetic resonance imaging (MRI), a relapse in the previous 2 years, or disease worsening in the previous 2 years.BHT-3009 was administered as intramuscular injections at weeks 1, 3, 5, and 9 after randomization into the trial, with or without 80 mg of daily oral atorvastatin calcium in combination. Three dose levels of BHT-3009 were tested (0.5 mg, 1.5 mg, and 3 mg).The primary outcome measures were safety and tolerability of BHT-3009. Secondary outcome measures included the number and volume of gadolinium-enhanced lesions on MRI, relapses, and analysis of antigen-specific immune responses.BHT-3009 was safe and well tolerated, provided favorable trends on brain MRI, and produced beneficial antigen-specific immune changes. These immune changes consisted of a marked decrease in proliferation of interferon-gamma-producing, myelin-reactive CD4+ T cells from peripheral blood and a reduction in titers of myelin-specific autoantibodies from cerebral spinal fluid as assessed by protein microarrays. We did not observe a substantial benefit of the atorvastatin combination compared with BHT-3009 alone.In patients with MS, BHT-3009 is safe and induces antigen-specific immune tolerance with concordant reduction of inflammatory lesions on brain MRI.

Abstract

alphaB-crystallin (CRYAB) is the most abundant gene transcript present in early active multiple sclerosis lesions, whereas such transcripts are absent in normal brain tissue. This crystallin has anti-apoptotic and neuroprotective functions. CRYAB is the major target of CD4+ T-cell immunity to the myelin sheath from multiple sclerosis brain. The pathophysiological implications of this immune response were investigated here. We demonstrate that CRYAB is a potent negative regulator acting as a brake on several inflammatory pathways in both the immune system and central nervous system (CNS). Cryab-/- mice showed worse experimental autoimmune encephalomyelitis (EAE) at the acute and progressive phases, with higher Th1 and Th17 cytokine secretion from T cells and macrophages, and more intense CNS inflammation, compared with their wild-type counterparts. Furthermore, Cryab-/- astrocytes showed more cleaved caspase-3 and more TUNEL staining, indicating an anti-apoptotic function of Cryab. Antibody to CRYAB was detected in cerebrospinal fluid from multiple sclerosis patients and in sera from mice with EAE. Administration of recombinant CRYAB ameliorated EAE. Thus, the immune response against a negative regulator of inflammation, CRYAB, in multiple sclerosis, would exacerbate inflammation and demyelination. This can be countered by giving CRYAB itself for therapy of ongoing disease.

Abstract

Peroxisome proliferator-activated receptor (PPAR)alpha is a nuclear receptor that mediates gender differences in lipid metabolism. PPARalpha also functions to control inflammatory responses by repressing the activity of nuclear factor kappaB (NF-kappaB) and c-jun in immune cells. Because PPARalpha is situated at the crossroads of gender and immune regulation, we hypothesized that this gene may mediate sex differences in the development of T cell-mediated autoimmune disease. We show that PPARalpha is more abundant in male as compared with female CD4(+) cells and that its expression is sensitive to androgen levels. Genetic ablation of this gene selectively removed the brake on NF-kappaB and c-jun activity in male T lymphocytes, resulting in higher production of interferon gamma and tumor necrosis factor (but not interleukin 17), and lower production of T helper (Th)2 cytokines. Upon induction of experimental autoimmune encephalomyelitis, male but not female PPARalpha(-/-) mice developed more severe clinical signs that were restricted to the acute phase of disease. These results suggest that males are less prone to develop Th1-mediated autoimmunity because they have higher T cell expression of PPARalpha.

A brief history of T(H)17, the first major revision in the T(H)1/T(H)2 hypothesis of T cell-mediated tissue damageNATURE MEDICINESteinman, L.2007; 13 (2): 139-145

Abstract

For over 35 years, immunologists have divided T-helper (T(H)) cells into functional subsets. T-helper type 1 (T(H)1) cells-long thought to mediate tissue damage-might be involved in the initiation of damage, but they do not sustain or play a decisive role in many commonly studied models of autoimmunity, allergy and microbial immunity. A major role for the cytokine interleukin-17 (IL-17) has now been described in various models of immune-mediated tissue injury, including organ-specific autoimmunity in the brain, heart, synovium and intestines, allergic disorders of the lung and skin, and microbial infections of the intestines and the nervous system. A pathway named T(H)17 is now credited for causing and sustaining tissue damage in these diverse situations. The T(H)1 pathway antagonizes the T(H)17 pathway in an intricate fashion. The evolution of our understanding of the T(H)17 pathway illuminates a shift in immunologists' perspectives regarding the basis of tissue damage, where for over 20 years the role of T(H)1 cells was considered paramount.

Abstract

Relapses and disease exacerbations are vexing features of multiple sclerosis. Osteopontin (Opn), which is expressed in multiple sclerosis lesions, is increased in patients' plasma during relapses. Here, in models of multiple sclerosis including relapsing, progressive and multifocal experimental autoimmune encephalomyelitis (EAE), Opn triggered recurrent relapses, promoted worsening paralysis and induced neurological deficits, including optic neuritis. Increased inflammation followed Opn administration, whereas its absence resulted in more cell death of brain-infiltrating lymphocytes. Opn promoted the survival of activated T cells by inhibiting the transcription factor Foxo3a, by activating the transcription factor NF-kappaB through induction of phosphorylation of the kinase IKKbeta and by altering expression of the proapoptotic proteins Bim, Bak and Bax. Those mechanisms collectively suppressed the death of myelin-reactive T cells, linking Opn to the relapses and insidious progression characterizing multiple sclerosis.

Abstract

3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase is a critical enzyme in the mevalonate pathway that regulates the biosynthesis of cholesterol as well as isoprenoids that mediate the membrane association of certain GTPases. Blockade of this enzyme by atorvastatin (AT) inhibits the destructive proinflammatory T helper cell (Th)1 response during experimental autoimmune encephalomyelitis and may be beneficial in the treatment of multiple sclerosis and other Th1-mediated autoimmune diseases. Here we present evidence linking specific isoprenoid intermediates of the mevalonate pathway to signaling pathways that regulate T cell autoimmunity. We demonstrate that the isoprenoid geranylgeranyl-pyrophosphate (GGPP) mediates proliferation, whereas both GGPP and its precursor, farnesyl-PP, regulate the Th1 differentiation of myelin-reactive T cells. Depletion of these isoprenoid intermediates in vivo via oral AT administration hindered these T cell responses by decreasing geranylgeranylated RhoA and farnesylated Ras at the plasma membrane. This was associated with reduced extracellular signal-regulated kinase (ERK) and p38 phosphorylation and DNA binding of their cotarget c-fos in response to T cell receptor activation. Inhibition of ERK and p38 mimicked the effects of AT and induced a Th2 cytokine shift. Thus, by connecting isoprenoid availability to regulation of Th1/Th2 fate, we have elucidated a mechanism by which AT may suppress Th1-mediated central nervous system autoimmune disease.

Abstract

Recent studies suggest that increased T-cell and autoantibody reactivity to lipids may be present in the autoimmune demyelinating disease multiple sclerosis. To perform large-scale multiplex analysis of antibody responses to lipids in multiple sclerosis, we developed microarrays composed of lipids present in the myelin sheath, including ganglioside, sulfatide, cerebroside, sphingomyelin and total brain lipid fractions. Lipid-array analysis showed lipid-specific antibodies against sulfatide, sphingomyelin and oxidized lipids in cerebrospinal fluid (CSF) derived from individuals with multiple sclerosis. Sulfatide-specific antibodies were also detected in SJL/J mice with acute experimental autoimmune encephalomyelitis (EAE). Immunization of mice with sulfatide plus myelin peptide resulted in a more severe disease course of EAE, and administration of sulfatide-specific antibody exacerbated EAE. Thus, autoimmune responses to sulfatide and other lipids are present in individuals with multiple sclerosis and in EAE, and may contribute to the pathogenesis of autoimmune demyelination.

Abstract

Local catabolism of the amino acid tryptophan (Trp) by indoleamine 2,3-dioxygenase (IDO) is considered an important mechanism of regulating T cell immunity. We show that IDO transcription was increased when myelin-specific T cells were stimulated with tolerogenic altered self-peptides. Catabolites of Trp suppressed proliferation of myelin-specific T cells and inhibited production of proinflammatory T helper-1 (T(H)1) cytokines. N-(3,4,-Dimethoxycinnamoyl) anthranilic acid (3,4-DAA), an orally active synthetic derivative of the Trp metabolite anthranilic acid, reversed paralysis in mice with experimental autoimmune encephalomyelitis, a model of multiple sclerosis (MS). Trp catabolites and their derivatives offer a new strategy for treating T(H)1-mediated autoimmune diseases such as MS.

Abstract

A better understanding of the molecules involved in immune responses has identified many potential targets for the treatment of autoimmune diseases. But although successful therapies have been found for immune disorders in animal studies, few have passed the much harder test of treating human diseases. So far, non-antigen-specific approaches, such as the blocking of tumour-necrosis factor, are achieving some success but the same is not true for antigen-specific approaches. Future therapies will probably include both non-antigen-specific strategies that target cytokines (cell-cell signalling molecules) or block the molecules that stimulate immune responses, and antigen-specific therapies that induce tolerance to self antigens.

Abstract

Immunologists have long hypothesized that particular 'molecular addresses' govern lymphocyte entry to a given organ. In 1992, alpha4beta1 integrin was identified as the key molecule involved in homing to inflamed regions of the brain. An antibody to alpha4beta1integrin blocked paralysis in an animal model of multiple sclerosis, and the humanized monoclonal antibody natalizumab, which binds alpha4beta1 integrin, reduced relapses 66% in clinical trials in multiple sclerosis. Three months after its expedited approval by the FDA, natalizumab was removed from the market after two cases of deadly progressive multifocal leukoencephalopathy were reported among the few thousand patients who had taken this drug in those clinical trials.

Abstract

Our increasing understanding of the pathophysiology of autoimmune disease has revealed a number of checkpoints that can be targeted with immune therapy, including key mediators of lymphocyte adhesion and migration, destructive cytokines involved in tissue damage, and the complex of molecules critical in the presentation of self-antigen and the activation of autoaggressive T lymphocytes. In many organ-specific autoimmune diseases, the identity of the molecules attacked by T cells and autoantibodies is known and attempts are under way to tolerize the immune system with a high level of specificity to these targets.

Abstract

Administration of a monoclonal antibody (GK1.5) that recognizes the L3T4 marker present on helper T cells prevented the development of experimental allergic encephalomyelitis (EAE) in mice. Furthermore, treatment with GK1.5 reversed EAE when the antibody was given to paralyzed animals. In vivo injection of GK1.5 selectively reduced the number of L3T4+ cells in the spleen and the lymph nodes. These results suggest that manipulation of the human equivalent of the murine L3T4+ T-cell subset with monoclonal antibodies may provide effective therapy for certain autoimmune diseases.

DISAPPEARANCE AND REAPPEARANCE OF B-CELLS AFTER INVIVO TREATMENT WITH MONOCLONAL ANTI-I-A ANTIBODIESPROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCESWaldor, M. K., Hardy, R. R., Hayakawa, K., Steinman, L., Herzenberg, L. A., Herzenberg, L. A.1984; 81 (9): 2855-2858

Abstract

Previous studies have shown that treatment with antibodies to the murine I-A antigen encoded in the major histocompatibility complex attenuates experimental allergic encephalitis and experimental autoimmune myasthenia gravis. These studies were conducted with SJL mice, an inbred strain that is highly susceptible to the induction of these diseases. Here we show that injection of monoclonal anti-I-A antibody in the amounts used for the above studies rapidly depletes B cells. Fluorescence-activated cell sorter (FACS) multiparameter analysis of the B-cell subpopulations in treated animals shows that maximum depletion occurs around 5 days after treatment and that recovery of some subpopulations i still incomplete 1 month later. SJL mice are more sensitive to this B-cell depletion and recover more slowly than putatively normal C3H.Ighb (CKB) mice. Some components of the primary, secondary and tertiary IgG antibody responses are reduced in anti-I-A-treated SJL animals immunized after the first and second anti-I-A injections. The persistence of some antibody response impairment well beyond the time when anti-I-A disappears raises a note of caution concerning human therapy protocols based on the injection of anti-Ia antibodies.

INVIVO THERAPY WITH MONOCLONAL ANTI-I-A ANTIBODY SUPPRESSES IMMUNE-RESPONSES TO ACETYLCHOLINE-RECEPTORPROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCESWaldor, M. K., Sriram, S., McDevitt, H. O., Steinman, L.1983; 80 (9): 2713-2717

Abstract

A monoclonal antibody to I-A gene products of the immune response gene complex attenuates both humoral and cellular responses to acetylcholine receptor and appears to suppress clinical manifestations of experimental autoimmune myasthenia gravis. This demonstrates that use of antibodies against immune response gene products that are associated with susceptibility to disease may be feasible for therapy in autoimmune conditions such as myasthenia gravis.

Abstract

To evaluate cerebrospinal fluid (CSF) cytokine profiles in myelin oligodendrocyte glycoprotein IgG-positive (MOG-IgG+) disease in adult and paediatric patients.In this cross-sectional study, we measured 27 cytokines in the CSF of MOG-IgG+ disease in acute phase before treatment (n=29). The data were directly compared with those in aquaporin-4 antibody-positive (AQP4-IgG+) neuromyelitis optica spectrum disorder (NMOSD) (n=20), multiple sclerosis (MS) (n=20) and non-inflammatory controls (n=14).In MOG-IgG+ disease, there was no female preponderance and the ages were younger (mean 18 years, range 3-68; 15 were below 18 years) relative to AQP4-IgG+ NMOSD (41, 15-77) and MS (34, 17-48). CSF cell counts were higher and oligoclonal IgG bands were mostly negative in MOG-IgG+ disease and AQP4-IgG+ NMOSD compared with MS. MOG-IgG+ disease had significantly elevated levels of interleukin (IL)-6, IL-8, granulocyte-colony stimulating factor and granulocyte macrophage-colony stimulating factor, interferon-γ, IL-10, IL-1 receptor antagonist, monocyte chemotactic protein-1 and macrophage inflammatory protein-1α as compared with MS. No cytokine in MOG-IgG+ disease was significantly different from AQP4-IgG+ NMOSD. Moreover many elevated cytokines were correlated with each other in MOG-IgG+ disease and AQP4-IgG+ NMOSD but not in MS. No difference in the data was seen between adult and paediatric MOG-IgG+ cases.The CSF cytokine profile in the acute phase of MOG-IgG+ disease is characterised by coordinated upregulation of T helper 17 (Th17) and other cytokines including some Th1-related and regulatory T cells-related ones in adults and children, which is similar to AQP4-IgG+ NMOSD but clearly different from MS. The results suggest that as with AQP4-IgG+ NMOSD, some disease-modifying drugs for MS may be ineffective in MOG-IgG+ disease while they may provide potential therapeutic targets.

Abstract

In patients with multiple sclerosis, the selective serotonin reuptake inhibitor, fluoxetine, resulted in less acute disease activity. We tested the immune modulating effects of fluoxetine in a mouse model of multiple sclerosis, i.e. experimental autoimmune encephalomyelitis (EAE). We show that fluoxetine delayed the onset of disease and reduced clinical paralysis in mice with established disease. Fluoxetine had abrogating effects on proliferation of immune cells and inflammatory cytokine production by both antigen-presenting cells and T cells. Specifically, in CD4 T cells, fluoxetine increased Fas-induced apoptosis. We conclude that fluoxetine possesses immune-modulating effects resulting in the amelioration of symptoms in EAE.

Abstract

Demyelinated brain lesions, a hallmark of autoimmune neuroinflammatory diseases like multiple sclerosis, result from oligodendroglial cell damage. Activated microglia are considered a major source of nitric oxide and subsequent peroxynitrite-mediated damage of myelin. Here, we provide biochemical and biophysical evidence that the oxidoreductase glutaredoxin 2 inhibits peroxynitrite formation by transforming nitric oxide into dinitrosyl-diglutathionyl-iron-complexes. Glutaredoxin 2 levels influence both survival rates of primary oligodendrocyte progenitor cells and preservation of myelin structure in cerebellar organotypic slice cultures challenged with activated microglia or nitric oxide donors. Of note, glutaredoxin 2-mediated protection is not linked to its enzymatic activity as oxidoreductase, but to the disassembly of its uniquely coordinated iron-sulfur cluster using glutathione as non-protein ligand. The protective effect of glutaredoxin 2 is connected to decreased protein carbonylation and nitration. In line, brain lesions of mice suffering from experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis, show decreased glutaredoxin 2 expression and increased nitrotyrosine formation indicating that this type of protection is missing in the inflamed central nervous system. Our findings link inorganic biochemistry to neuroinflammation and identify glutaredoxin 2 as a protective factor against neuroinflammation-mediated myelin damage. Thus, improved availability of glutathione-coordinated iron-sulfur clusters emerges as a potential therapeutic approach in inflammatory demyelination.

Abstract

To determine the average age of MS onset vs the age at which Epstein-Barr infection has previously occurred and stratify this analysis by sex and the blood level of Epstein-Barr nuclear antigen 1 (EBNA1) antibody.Using infectious mononucleosis (IM) as a temporal marker in data from the Swedish epidemiologic investigation of MS, 259 adult IM/MS cases were identified and then augmented to account for "missing" childhood data so that the average age of MS onset could be determined for cases binned by age of IM (as stratified by sex and EBNA1 titer level).Mean age of IM vs mean age of MS reveals a positive time correlation for all IM ages (from ∼5 to ∼30 years), with IM-to-MS delay decreasing with increased age. When bifurcated by sex or EBNA1 blood titer levels, males and high-titer subpopulations show even stronger positive time correlation, while females and low-titer populations show negative time correlation in early childhood (long IM/MS delay). The correlation becomes positive in females beyond puberty.IM/MS time correlation implies causality if IM is time random. Alternative confounding models seem implausible, in light of constraints imposed by time-invariant delay observed here. Childhood infection with Epstein-Barr virus (EBV) in females and/or those genetically prone to low EBNA1 blood titers will develop MS slowly. Males and/or high EBNA1-prone develop MS more rapidly following IM infection at all ages. For all, postpubescent EBV infection is critical for the initiation and rapid development of MS.

Abstract

Expression of Spam1/PH20 and its modulation of high/low molecular weight hyaluronan substrate have been proposed to play an important role in murine oligodendrocyte precursor cell (OPC) maturation in vitro and in normal and demyelinated central nervous system (CNS). We reexamined this using highly purified PH20.Steady-state expression of mRNA in OPCs was evaluated by quantitative polymerase chain reaction; the role of PH20 in bovine testicular hyaluronidase (BTH) inhibition of OPC differentiation was explored by comparing BTH to a purified recombinant human PH20 (rHuPH20). Contaminants in commercial BTH were identified and their impact on OPC differentiation characterized. Spam1/PH20 expression in normal and demyelinated mouse CNS tissue was investigated using deep RNA sequencing and immunohistological methods with two antibodies directed against recombinant murine PH20.BTH, but not rHuPH20, inhibited OPC differentiation in vitro. Basic fibroblast growth factor (bFGF) was identified as a significant contaminant in BTH, and bFGF immunodepletion reversed the inhibitory effects of BTH on OPC differentiation. Spam1 mRNA was undetected in OPCs in vitro and in vivo; PH20 immunolabeling was undetected in normal and demyelinated CNS.We were unable to detect Spam1/PH20 expression in OPCs or in normal or demyelinated CNS using the most sensitive methods currently available. Further, "BTH" effects on OPC differentiation are not due to PH20, but may be attributable to contaminating bFGF. Our data suggest that caution be exercised when using some commercially available hyaluronidases, and reports of Spam1/PH20 morphogenic activity in the CNS may be due to contaminants in reagents.

Abstract

The small heat shock protein αB-crystallin (CRYAB) has been implicated in multiple sclerosis (MS) pathogenesis. Earlier studies have indicated that CRYAB inhibits inflammation and attenuates clinical disease when administered in the experimental autoimmune encephalomyelitis model of MS. In this study, we evaluated the role of CRYAB in primary demyelinating events. Using the cuprizone model of demyelination, a noninflammatory model that allows the analysis of glial responses in MS, we show that endogenous CRYAB expression is associated with increased severity of demyelination. Moreover, we demonstrate a strong correlation between the expression of CRYAB and the extent of reactive astrogliosis in demyelinating areas and in in vitro assays. In addition, we reveal that CRYAB is differentially phosphorylated in astrocytes in active demyelinating MS lesions, as well as in cuprizone-induced lesions, and that this phosphorylation is required for the reactive astrocyte response associated with demyelination. Furthermore, taking a proteomics approach to identify proteins that are bound by the phosphorylated forms of CRYAB in primary cultured astrocytes, we show that there is clear differential binding of protein targets due to the specific phosphorylation of CRYAB. Subsequent Ingenuity Pathway Analysis of these targets reveals implications for intracellular pathways and biological processes that could be affected by these modifications. Together, these findings demonstrate that astrocytes play a pivotal role in demyelination, making them a potential target for therapeutic intervention, and that phosphorylation of CRYAB is a key factor supporting the pathogenic response of astrocytes to oligodendrocyte injury.

Abstract

Aquaporin-4 (AQP4)-specific T cells are expanded in neuromyelitis optica (NMO) patients and exhibit Th17 polarization. However, their pathogenic role in CNS autoimmune inflammatory disease is unclear. Although multiple AQP4 T-cell epitopes have been identified in WT C57BL/6 mice, we observed that neither immunization with those determinants nor transfer of donor T cells targeting them caused CNS autoimmune disease in recipient mice. In contrast, robust proliferation was observed following immunization of AQP4-deficient (AQP4(-/-)) mice with AQP4 peptide (p) 135-153 or p201-220, peptides predicted to contain I-A(b)-restricted T-cell epitopes but not identified in WT mice. In comparison with WT mice, AQP4(-/-) mice used unique T-cell receptor repertoires for recognition of these two AQP4 epitopes. Donor T cells specific for either determinant from AQP4(-/-), but not WT, mice induced paralysis in recipient WT and B-cell-deficient mice. AQP4-specific Th17-polarized cells induced more severe disease than Th1-polarized cells. Clinical signs were associated with opticospinal infiltrates of T cells and monocytes. Fluorescent-labeled donor T cells were detected in CNS lesions. Visual system involvement was evident by changes in optical coherence tomography. Fine mapping of AQP4 p201-220 and p135-153 epitopes identified peptides within p201-220 but not p135-153, which induced clinical disease in 40% of WT mice by direct immunization. Our results provide a foundation to evaluate how AQP4-specific T cells contribute to AQP4-targeted CNS autoimmunity (ATCA) and suggest that pathogenic AQP4-specific T-cell responses are normally restrained by central tolerance, which may be relevant to understanding development of AQP4-reactive T cells in NMO.

Abstract

Neuromyelitis optica spectrum disorder (NMO/SD) and its clinical variants have at their core the loss of immune tolerance to aquaporin-4 and perhaps other autoantigens. The characteristic phenotype is disruption of astrocyte function and demyelination of spinal cord, optic nerves, and particular brain regions. In this second of a 2-part article, we present further perspectives regarding the pathogenesis of NMO/SD and how this disease might be amenable to emerging technologies aimed at restoring immune tolerance to disease-implicated self-antigens. NMO/SD appears to be particularly well-suited for these strategies since aquaporin-4 has already been identified as the dominant autoantigen. The recent technical advances in reintroducing immune tolerance in experimental models of disease as well as in humans should encourage quantum leaps in this area that may prove productive for novel therapy. In this part of the article series, the potential for regulatory T and B cells is brought into focus, as are new approaches to oral tolerization. Finally, a roadmap is provided to help identify potential issues in clinical development and guide applications in tolerization therapy to solving NMO/SD through the use of emerging technologies. Each of these perspectives is intended to shine new light on potential cures for NMO/SD and other autoimmune diseases, while sparing normal host defense mechanisms.

Abstract

Neuromyelitis optica (NMO) and spectrum disorder (NMO/SD) represent a vexing process and its clinical variants appear to have at their pathogenic core the loss of immune tolerance to the aquaporin-4 water channel protein. This process results in a characteristic pattern of astrocyte dysfunction, loss, and demyelination that predominantly affects the spinal cord and optic nerves. Although several empirical therapies are currently used in the treatment of NMO/SD, none has been proven effective in prospective, adequately powered, randomized trials. Furthermore, most of the current therapies subject patients to long-term immunologic suppression that can cause serious infections and development of cancers. The following is the first of a 2-part description of several key immune mechanisms in NMO/SD that might be amenable to therapeutic restoration of immune tolerance. It is intended to provide a roadmap for how potential immune tolerance restorative techniques might be applied to patients with NMO/SD. This initial installment provides a background rationale underlying attempts at immune tolerization. It provides specific examples of innovative approaches that have emerged recently as a consequence of technical advances. In several autoimmune diseases, these strategies have been reduced to practice. Therefore, in theory, the identification of aquaporin-4 as the dominant autoantigen makes NMO/SD an ideal candidate for the development of tolerizing therapies or cures for this increasingly recognized disease.

Abstract

Amyloid hexapeptide molecules are effective in the treatment of the murine model of neuroinflammation, known as experimental autoimmune encephalomyelitis (EAE). Efficacy however differs between two inbred mouse strains, C57BL/6J (B6) and C57BL/10SnJ (B10). Amyloid hexapeptide treatments improved the clinical outcomes of B6, but not B10 mice, indicating that genetic background influences therapeutic efficacy. Moreover, although previous studies indicated that prion protein deficiency results in more severe EAE in B6 mice, we observed no such effect in B10 mice. In addition, we found that amyloid hexapeptide treatments of B10 and B6 mice elicited differential IL4 responses. Thus, the modulatory potential of prion protein and related treatments with other amyloid hexapeptides in EAE depends on mouse strain.

Abstract

Recently, there has been considerable interest in using 4-methylumbelliferone (4-MU) to inhibit hyaluronan synthesis in mouse models of cancer, autoimmunity, and a variety of other inflammatory disorders where hyaluronan (HA) has been implicated in disease pathogenesis. In order to facilitate future studies in this area, we have examined the dosing, treatment route, treatment duration, and metabolism of 4-MU in both C57BL/6 and BALB/c mice. Mice fed chow containing 5% 4-MU, a dose calculated to deliver 250 mg/mouse/day, initially lose substantial weight but typically resume normal weight gain after one week. It also takes up to a week to see a reduction in serum HA in these animals, indicating that at least a one-week loading period on the drug is required for most protocols. At steady state, over 90% of the drug is present in plasma as the glucuronidated metabolite 4-methylumbelliferyl glucuronide (4-MUG), with the sulfated metabolite, 4-methylumbelliferyl sulfate (4-MUS) comprising most of the remainder. Chow containing 5% but not 0.65% 4-MU was effective at preventing disease in the experimental autoimmune encephalomyelitis (EAE) mouse model of multiple sclerosis as well as in the DORmO mouse model of autoimmune diabetes. While oral 4-MU was effective at preventing EAE, daily intraperitoneal injections of 4-MU were not. Factors potentially affecting 4-MU uptake and plasma concentrations in mice include its taste, short half-life and low bioavailability. These studies provide a practical resource for implementing oral 4-MU treatment protocols in mice. This article is protected by copyright. All rights reserved.

Abstract

B cell aggregates in the central nervous system (CNS) have been associated with rapid disease progression in patients with multiple sclerosis (MS). Here we demonstrate a key role of carcinoembryogenic antigen-related cell adhesion molecule1 (CEACAM1) in B cell aggregate formation in MS patients and a B cell-dependent mouse model of MS. CEACAM1 expression was increased on peripheral blood B cells and CEACAM1(+) B cells were present in brain infiltrates of MS patients. Administration of the anti-CEACAM1 antibody T84.1 was efficient in blocking aggregation of B cells derived from MS patients. Along these lines, application of the monoclonal anti-CEACAM1 antibody mCC1 was able to inhibit CNS B cell aggregate formation and significantly attenuated established MS-like disease in mice in the absence of any adverse effects. CEACAM1 was co-expressed with the regulator molecule T cell immunoglobulin and mucin domain -3 (TIM-3) on B cells, a novel molecule that has recently been described to induce anergy in T cells. Interestingly, elevated coexpression on B cells coincided with an autoreactive T helper cell phenotype in MS patients. Overall, these data identify CEACAM1 as a clinically highly interesting target in MS pathogenesis and open new therapeutic avenues for the treatment of the disease.

Abstract

The review discusses future directions in research on multiple sclerosis and neuromyelitis optica, as long-held beliefs about these diseases are undermined with data from recent clinical trials.Results of clinical trials for registration (phase 3) were reported in the last year. Anti-inflammatory approaches, such as daclizumab high-yield process targeting IL-2 receptor, and ocrelizumab targeting CD20 B cells, confirmed a beneficial role of immune suppression in relapsing-remitting disease. And now for the first time achieving the primary end point in primary progressive multiple sclerosis was attained with ocrelizumab.The results in the past year challenge the long-held belief that relapsing-remitting disease is inflammatory, whereas progressive forms of the disease are 'less inflammatory' and more 'degenerative.'

Abstract

Type I interferon (IFN) signaling is a central pathogenic pathway in systemic lupus erythematosus (SLE), and therapeutics targeting type I IFN signaling are in development. Multiple proteins with overlapping functions play a role in IFN signaling, but the signaling events downstream of receptor engagement are unclear. This study was undertaken to investigate the roles of the type I and type II IFN signaling components IFN-α/β/ω receptor 2 (IFNAR-2), IFN regulatory factor 9 (IRF-9), and STAT-1 in a mouse model of SLE.We used immunohistochemical staining and highly multiplexed assays to characterize pathologic changes in histology, autoantibody production, cytokine/chemokine profiles, and STAT phosphorylation in order to investigate the individual roles of IFNAR-2, IRF-9, and STAT-1 in MRL/lpr mice.We found that STAT-1(-/-) mice, but not IRF-9(-/-) or IFNAR-2(-/-) mice, developed interstitial nephritis characterized by infiltration with retinoic acid receptor-related orphan nuclear receptor γt-positive lymphocytes, macrophages, and eosinophils. Despite pronounced interstitial kidney disease and abnormal kidney function, STAT-1(-/-) mice had decreased proteinuria, glomerulonephritis, and autoantibody production. Phosphospecific flow cytometry revealed shunting of STAT phosphorylation from STAT-1 to STAT-3/4.We describe unique contributions of STAT-1 to pathology in different kidney compartments in a mouse model, and provide potentially novel insight into tubulointerstitial nephritis, a poorly understood complication that predicts end-stage kidney disease in SLE patients.

Abstract

To evaluate serum cytokine profiles for their utility to determine the heterogeneous responses to interferon (IFN)-β treatment in patients with multiple sclerosis (MS).Patients with relapsing-remitting MS (RRMS) or clinically isolated syndrome receiving de novo IFN-β treatment were included in this prospective, observational study. Number of relapses and changes in disability were assessed 2 years prior to and 2 years after initiation of treatment. Sera were collected at baseline and after 3 months on therapy. Cytokine levels in sera were assessed by Luminex multiplex assays. Baseline cytokine profiles were grouped by hierarchical clustering analysis. Demographic features, changes in cytokines, and clinical outcome were then assessed in the clustered patient groups.A total of 157 patients were included in the study and clustered into 6 distinct subsets by baseline cytokine profiles. These subsets differed significantly in their clinical and biological response to IFN-β therapy. Two subsets were associated with patients who responded poorly to therapy. Two other subsets, associated with a good response to therapy, showed a significant reduction in relapse rates and no worsening of disability. Each subset also had differential changes in cytokine levels after 3 months of IFN-β treatment.There is heterogeneity in the immunologic pathways of the RRMS population, which correlates with IFN-β response.

Abstract

Diabetes mellitus occurs spontaneously in dogs. Although canine diabetes shares many features with human type-1 diabetes, there are differences that have cast doubt on the immunologic origin of the canine disease. In this study, we examined whether peripheral immune responses directed against islet antigens were present in dogs with diabetes. Routine diagnostics were used to confirm diabetic status, and serum samples from dogs with (N = 15) and without (N = 15) diabetes were analyzed for the presence of antibodies against islet antigens (insulin, glutamic acid decarboxylase, insulinoma-associated protein tyrosine phosphatase, and islet beta-cell zinc cation efflux transporter) using standard radioassays. Interferon-γ production from peripheral blood T cells stimulated by porcine insulin and by human insulin was tested using Elispot assays. Anti-insulin antibodies were detectable in a subset of diabetic dogs receiving insulin therapy. Pre-activated T cells and incipient insulin-reactive T cells in response to porcine or human insulin were identified in non-diabetic dogs and in dogs with diabetes. The data show that humoral and cellular anti-insulin immune responses are detectable in dogs with diabetes. This in turn provides support for the potential to ethically use dogs with diabetes to study the therapeutic potential of antigen-specific tolerance.

Abstract

Despite the very high benefit-to-risk ratio of vaccines, the fear of negative side effects has discouraged many people from getting vaccinated, resulting in the reemergence of previously controlled diseases such as measles, pertussis and diphtheria. This fear has been amplified more recently by multiple epidemiologic studies that confirmed the link of an AS03-adjuvanted pandemic influenza vaccine (Pandemrix, GlaxoSmithKline Biologicals, Germany) used in Europe during the 2009 H1N1 influenza pandemic [A(H1N1) pdm09] with the development of narcolepsy, a chronic sleep disorder, in children and adolescents. However, public misperceptions of what adjuvants are and why they are used in vaccines has created in some individuals a closed "black box" attitude towards all vaccines. The focus of this review article is to revisit this "black box" using the example of narcolepsy associated with the European AS03-adjuvanted pandemic influenza vaccine.

Abstract

Patients with pemphigus vulgaris (PV) harbor antibodies reactive against self-antigens expressed at the surface of keratinocytes, primarily desmoglein (Dsg) 3 and, to a lesser extent, Dsg1. Conventionally, only antibodies targeting these molecules have been thought to contribute to disease pathogenesis. This notion has been challenged by a growing pool of evidence that suggests that antibodies toward additional targets may play a role in disease. The aims of this study were to (i) establish high-throughput protein microarray technology as a method to investigate traditional and putative autoantibodies (autoAbs) in PV and (ii) use multiplexed protein array technology to define the scope and specificity of the autoAb response in PV. Our analysis demonstrated significant IgG reactivity in patients with PV toward the muscarinic acetylcholine receptor subtypes 3, 4, and 5 as well as thyroid peroxidase. Furthermore, we found that healthy first- and second-degree relatives of patients with PV express autoAbs toward desmoglein and non-Dsg targets. Our analysis also identified genetic elements, particularly HLA, as key drivers of autoAb expression. Finally, we show that patients with PV exhibit significantly reduced IgM reactivity toward disease-associated antigens relative to controls. The use of protein microarrays to profile the autoAb response in PV advanced the current understanding of disease and provided insight into the complex relationship between genetics and disease development.

Abstract

The extracellular matrix polysaccharide hyaluronan (HA) accumulates at sites of autoimmune inflammation, including white matter lesions in multiple sclerosis (MS), but its functional importance in pathogenesis is unclear. We have evaluated the impact of 4-methylumbelliferone (4-MU), an oral inhibitor of HA synthesis, on disease progression in the experimental autoimmune encephalomyelitis (EAE) mouse model of MS. Treatment with 4-MU decreases the incidence of EAE, delays its onset, and reduces the severity of established disease. 4-MU inhibits the activation of autoreactive T cells and prevents their polarization toward a Th1 phenotype. Instead, 4-MU promotes polarization toward a Th2 phenotpye and induction of Foxp3(+) regulatory T cells. Further, 4-MU hastens trafficking of T cells through secondary lymphoid organs, impairs the infiltration of T cells into the CNS parenchyma, and limits astrogliosis. Together, these data suggest that HA synthesis is necessary for disease progression in EAE and that treatment with 4-MU may be a potential therapeutic strategy in CNS autoimmunity. Considering that 4-MU is already a therapeutic, called hymecromone, that is approved to treat biliary spasm in humans, we propose that it could be repurposed to treat MS.

Abstract

To study the safety profile and characterize the immunologic effects of high- vs low-dose cholecalciferol supplementation in patients with multiple sclerosis (MS).In this double-blind, single-center randomized pilot study, 40 patients with relapsing-remitting MS were randomized to receive 10,400 IU or 800 IU cholecalciferol daily for 6 months. Assessments were performed at baseline and 3 and 6 months.Mean increase of 25-hydroxyvitamin D levels from baseline to final visit was larger in the high-dose group (34.9 ng/mL; 95% confidence interval [CI] 25.0-44.7 ng/mL) than in the low-dose group (6.9 ng/mL; 95% CI 1.0-13.7 ng/mL). Adverse events were minor and did not differ between the 2 groups. Two relapses occurred, one in each treatment arm. In the high-dose group, we found a reduction in the proportion of interleukin-17(+)CD4(+) T cells (p = 0.016), CD161(+)CD4(+) T cells (p = 0.03), and effector memory CD4(+) T cells (p = 0.021) with a concomitant increase in the proportion of central memory CD4(+) T cells (p = 0.018) and naive CD4(+) T cells (p = 0.04). These effects were not observed in the low-dose group.Cholecalciferol supplementation with 10,400 IU daily is safe and tolerable in patients with MS and exhibits in vivo pleiotropic immunomodulatory effects in MS, which include reduction of interleukin-17 production by CD4(+) T cells and decreased proportion of effector memory CD4(+) T cells with concomitant increase in central memory CD4(+) T cells and naive CD4(+) T cells.This study provides Class I evidence that cholecalciferol supplementation with 10,400 IU daily is safe and well-tolerated in patients with MS and exhibits in vivo pleiotropic immunomodulatory effects.

Abstract

Type 1 diabetes is an autoimmune disease in which insulin-producing pancreatic islet β cells are the target of self-reactive B and T cells. T cells reactive with epitopes derived from insulin and/or IGRP are critical for the initiation and maintenance of disease, but T cells reactive with other islet antigens likely have an essential role in disease progression. We sought to identify candidate CD8(+) T cell epitopes that are pathogenic in type 1 diabetes. Proteins that elicit autoantibodies in human type 1 diabetes were analyzed by predictive algorithms for candidate epitopes. Using several different tolerizing regimes using synthetic peptides, two new predicted tolerogenic CD8(+) T cell epitopes were identified in the murine homolog of the major human islet autoantigen zinc transporter ZnT8 (aa 158-166 and 282-290) and one in a non-β cell protein, dopamine β-hydroxylase (aa 233-241). Tolerizing vaccination of NOD mice with a cDNA plasmid expressing full-length proinsulin prevented diabetes, whereas plasmids encoding ZnT8 and DβH did not. However, tolerizing vaccination of NOD mice with the proinsulin plasmid in combination with plasmids expressing ZnT8 and DβH decreased insulitis and enhanced prevention of disease compared to vaccination with the plasmid encoding proinsulin alone.

Abstract

We previously reported an increased frequency of antibodies to hypocretin (HCRT) receptor 2 in sera obtained from narcoleptic patients who received the European AS03-adjuvanted vaccine Pandemrix (GlaxoSmithKline Biologicals, s.a.) for the global influenza A H1N1 pandemic in 2009 [A(H1N1)pdm09]. These antibodies cross-reacted with a particular fragment of influenza nucleoprotein (NP) - one of the proteins naturally contained in the virus used to make seasonal influenza vaccine and pandemic influenza vaccines. The purpose of this commentary is to provide additional insights and interpretations of the findings and share additional data not presented in the original paper to help the reader appreciate the key messages of that publication. First, a brief background to narcolepsy and vaccine-induced narcolepsy will be provided. Then, additional insights and clarification will be provided on the following topics: 1) the critical difference identified in the adjuvanted A(H1N1)pdm09 vaccines, 2) the contributing factor likely for the discordant association of narcolepsy between the AS03-adjuvanted pandemic vaccines Pandemrix and Arepanrix (GlaxoSmithKline Biologicals, s.a.), 3) the significance of detecting HCRT receptor 2 (HCRTr2) antibodies in some Finnish control subjects, 4) the approach used for the detection of HCRTr2 antibodies in vaccine-associated narcolepsy, and 5) the plausibility of the proposed mechanism involving HCRTr2 modulation in vaccine-associated narcolepsy.

Abstract

Vassalli et al.'s study does not involve or provide additional data regarding influenza virus, influenza vaccines, human samples, animal models of narcolepsy, or experiments related to mimicry and cross-reactivity. They present data on the distribution of hypocretin (HCRT) (also known as orexin) receptors in the brain of an engineered mouse developed by them.

Abstract

Multiple sclerosis is a serious neurological disorder, resulting in e.g., sensory, motor and cognitive deficits. A critical pathological aspect of multiple sclerosis (MS) is the influx of immunomodulatory cells into the central nervous system (CNS). Identification of key players that regulate cellular trafficking into the CNS may lead to the development of more selective treatment to halt this process. The multifunctional enzyme tissue Transglutaminase (TG2) can participate in various inflammation-related processes, and is known to be expressed in the CNS. In the present study, we question whether TG2 activity contributes to the pathogenesis of experimental MS, and could be a novel therapeutic target. In human post-mortem material, we showed the appearance of TG2 immunoreactivity in leukocytes in MS lesions, and particular in macrophages in rat chronic-relapsing experimental autoimmune encephalomyelitis (cr-EAE), an experimental MS model. Clinical deficits as observed in mouse EAE were reduced in TG2 knock-out mice compared to littermate wild-type mice, supporting a role of TG2 in EAE pathogenesis. To establish if the enzyme TG2 represents an attractive therapeutic target, cr-EAE rats were treated with TG2 activity inhibitors during ongoing disease. Reduction of TG2 activity in cr-EAE animals dramatically attenuated clinical deficits and demyelination. The mechanism underlying these beneficial effects pointed toward a reduction in macrophage migration into the CNS due to attenuated cytoskeletal flexibility and RhoA GTPase activity. Moreover, iNOS and TNFα levels were selectively reduced in the CNS of cr-EAE rats treated with a TG2 activity inhibitor, whereas other relevant inflammatory mediators were not affected in CNS or spleen by reducing TG2 activity. We conclude that modulating TG2 activity opens new avenues for therapeutic intervention in MS which does not affect peripheral levels of inflammatory mediators.

Abstract

A domain of erythropoietin (EPO), separate from the domain involved in red blood cell development, has been identified. This region of EPO has anti-inflammatory and neuroprotective effects. Use of a peptide sequence from this region provides the potential for an effective therapeutic without effects on erythropoiesis.

Abstract

Ideal therapy for inflammatory disease in the nervous system would preserve normal immune function, while suppressing only the pathologic immune responses that damage tissue and allowing for repair. In principle, antigen-specific therapy would eradicate unwanted adaptive immune responses-antibody and T-cell mediated--while preserving the integrity of other adaptive responses to infectious agents and retaining the ability to fight malignancy. However, at this time, for multiple sclerosis (MS) we do not have compelling evidence that would support any particular dominant immune response to any specific antigen or even a limited group of antigens. In fact, there are adaptive immune responses to a wide swathe of proteins and lipids found on neurons and myelin in MS. Unless controlling a few of the known immune responses is sufficient, antigen-specific therapy in MS may not have enough of an impact to modulate clinical outcome. However, in other neuroinflammatory conditions, such as neuromyelitis optica, the adaptive immune response is highly focused. Trials of antigen-specific therapy for neuroinflammatory disease might first be tested in diseases with a more limited adaptive immune response like neuromyelitis optica. The likelihood of a significant success for this therapeutic strategy might then ensue.

Abstract

Understanding the consequences of tuning TCR signaling on selection, peripheral T cell function, and tolerance in the context of native TCR repertoires may provide insight into the physiological control of tolerance. In this study, we show that genetic ablation of a natural tuner of TCR signaling, mir-181a-1/b-1, in double-positive thymocytes dampened TCR and Erk signaling and increased the threshold of positive selection. Whereas mir-181a-1/b-1 deletion in mice resulted in an increase in the intrinsic reactivity of naive T cells to self-antigens, it did not cause spontaneous autoimmunity. Loss of mir-181a-1/b-1 dampened the induction of experimental autoimmune encephalomyelitis and reduced basal TCR signaling in peripheral T cells and their migration from lymph nodes to pathogenic sites. Taken together, these results demonstrate that tolerance can be modulated by microRNA gene products through the control of opposing activities in T cell selection and peripheral T cell function.

Abstract

A panel of researchers working in different areas of adjuvanted vaccines deliberated over the topic, "Gaps in knowledge and prospects for research of adjuvanted vaccines" at, "Enhancing Vaccine Immunity and Value" conference held in July 2014. Several vaccine challenges and applications for new adjuvant technologies were discussed.

Abstract

To investigate the potential role of prokineticin 2 (PK2), a bioactive peptide involved in multiple biological functions including immune modulation, in CNS autoimmune demyelinating disease.We investigated the expression of PK2 in mice with experimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis (MS), and in patients with relapsing-remitting MS. We evaluated the biological effects of PK2 on expression of EAE and on development of T-cell response against myelin by blocking PK2 in vivo with PK2 receptor antagonists. We treated with PK2 immune cells activated against myelin antigen to explore the immune-modulating effects of this peptide in vitro.Pk2 messenger RNA was upregulated in spinal cord and lymph node cells (LNCs) of mice with EAE. PK2 protein was expressed in EAE inflammatory infiltrates and was increased in sera during EAE. In patients with relapsing-remitting MS, transcripts for PK2 were significantly increased in peripheral blood mononuclear cells compared with healthy controls, and PK2 serum concentrations were significantly higher. A PK2 receptor antagonist prevented or attenuated established EAE in chronic and relapsing-remitting models, reduced CNS inflammation and demyelination, and decreased the production of interferon (IFN)-γ and interleukin (IL)-17A cytokines in LNCs while increasing IL-10. PK2 in vitro increased IFN-γ and IL-17A and reduced IL-10 in splenocytes activated against myelin antigen.These data suggest that PK2 is a critical immune regulator in CNS autoimmune demyelination and may represent a new target for therapy.

Abstract

Natalizumab treatment alters peripheral CD4 cells counts in multiple sclerosis (MS) patients, providing a way to monitor the pharmacodynamic effects of the drug. The study was undertaken to assess whether CD4 cell counts correlate with different phases of natalizumab treatment of relapsing MS patients, including during a 12-week planned treatment interruption, and whether that might provide insights on lymphocyte trafficking. Clinical outcomes, MRI data, and CD4 cell counts were assessed at baseline prior to initiating natalizumab, while on regular dosing, at the end of the 12-week extended dosing interval, and at the time of reinitiation of natalizumab. The 12-week interruption was well tolerated and not associated with return of MS activity, disability progression, or new or worsened MRI data. Observed significant shifts in CD4 counts - dramatically increasing from the baseline while on treatment and decreasing back to the baseline level off treatment, then rising in a similar manner on natalizumab reinitiation, suggest that these measurements may aid in monitoring modulation of lymphocyte trafficking and cell redistribution.

Abstract

IFN-β remains the most widely prescribed treatment for relapsing remitting multiple sclerosis. Despite widespread use of IFN-β, the therapeutic mechanism is still partially understood. Particularly, the clinical relevance of increased B cell activity during IFN-β treatment is unclear. In this article, we show that IFN-β pushes some B cells into a transitional, regulatory population that is a critical mechanism for therapy. IFN-β treatment increases the absolute number of regulatory CD19(+)CD24(++)CD38(++) transitional B cells in peripheral blood relative to treatment-naive and Copaxone-treated patients. In addition, we found that transitional B cells from both healthy controls and IFN-β-treated MS patients are potent producers of IL-10, and that the capability of IFN-β to induce IL-10 is amplified when B cells are stimulated. Similar changes are seen in mice with experimental autoimmune encephalomyelitis. IFN-β treatment increases transitional and regulatory B cell populations, as well as IL-10 secretion in the spleen. Furthermore, we found that IFN-β increases autoantibody production, implicating humoral immune activation in B cell regulatory responses. Finally, we demonstrate that IFN-β therapy requires immune-regulatory B cells by showing that B cell-deficient mice do not benefit clinically or histopathologically from IFN-β treatment. These results have significant implications for the diagnosis and treatment of relapsing remitting multiple sclerosis.

Abstract

Prolactin (PRL) has long been proposed as an immune-stimulating and detrimental factor in autoimmune disorders. However, recent findings have challenged this common view, showing that PRL does not play a crucial role in the development of experimental autoimmune encephalomyelitis, animal model for multiple sclerosis (MS), and even protects against adjuvant-induced model of rheumatoid arthritis (RA). In this review we provide a critical overview of data supporting a role for PRL in the regulation of immune responses. In addition, we focus on studies exploring the involvement of PRL in autoimmune diseases, such as systemic lupus erythematosus, MS and RA, in light of the recently-outlined regenerative properties of this hormone.

Abstract

Each year, 10 million people worldwide survive the neurologic injury associated with a stroke. Importantly, stroke survivors have more than twice the risk of subsequently developing dementia compared with people who have never had a stroke. The link between stroke and the later development of dementia is not understood. There are reports of oligoclonal bands in the CSF of stroke patients, suggesting that in some people a B-lymphocyte response to stroke may occur in the CNS. Therefore, we tested the hypothesis that a B-lymphocyte response to stroke could contribute to the onset of dementia. We discovered that, in mouse models, activated B-lymphocytes infiltrate infarcted tissue in the weeks after stroke. B-lymphocytes undergo isotype switching, and IgM, IgG, and IgA antibodies are found in the neuropil adjacent to the lesion. Concurrently, mice develop delayed deficits in LTP and cognition. Genetic deficiency, and the pharmacologic ablation of B-lymphocytes using an anti-CD20 antibody, prevents the appearance of delayed cognitive deficits. Furthermore, immunostaining of human postmortem tissue revealed that a B-lymphocyte response to stroke also occurs in the brain of some people with stroke and dementia. These data suggest that some stroke patients may develop a B-lymphocyte response to stroke that contributes to dementia, and is potentially treatable with FDA-approved drugs that target B cells.

Abstract

Inflammatory conditions intensify and then resolve, often sparing and recovering some of the injured tissue. While the ebb and flow of inflammation can be followed in many tissues, there is not a great deal of information on how inflammation regresses in the brain. In this issue of the JCI, Walsh, Hendrix, and colleagues illuminate a cellular mechanism whereby T cells that infiltrate the brain after nerve crush or contusion actually protect neurons from injury. These infiltrating T cells produce IL-4 and do so independently of a classic adaptive T cell immune response. The T cells respond to mediators produced by damaged neurons, without the classic three-way interaction among antigen, the major histocompatibility complex, and the T cell receptor. After brain injury, these protective T cells produce IL-4, which attenuates damage via IL-4 receptors on neurons.

A century of pavlovian experiments forming a circuit from the elucidation of neural reflexes to pharmaceuticals and electroceuticals to treat diseasesBRAIN BEHAVIOR AND IMMUNITYSteinman, L.2015; 44: 17–18

Abstract

Amyloidogenic proteins have long been linked to neurodegenerative diseases. However, amyloid fibrils composed of six amino acids are protective in an animal model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE). The reduction of pro-inflammatory cytokines, decrease in the number of inflammatory foci in the parenchyma and meninges of the brain and spinal cord, and amelioration of the neurological signs of EAE when amyloid fibril-forming hexapeptides are administered reveal that some fibrils provide benefit. The therapeutic activity of the amyloid fibrils arise from diverse pathways that include binding of pro-inflammatory mediators in the plasma, reduction of IL-6, TNF-α, and IFN-γ levels, and induction of type 1 interferon (IFN). Type 1 IFN has been used widely as a therapeutic agent for the treatment of MS and has been shown to be therapeutic in EAE with adoptive transfer of Th1 lymphocytes. However, type 1 IFN is known to exacerbate EAE with adoptive transfer of Th17 lymphocytes. Indeed, the amyloid fibril-forming peptide Tau 623-628 was therapeutic in Th1 adoptively transferred EAE, but ineffective in Th17 adoptively transferred EAE. However, the therapeutic effect of Tau 623-628 was restored in IFN-α/β receptor (IFNAR) knockout mice, indicating that other immune pathways independent of type 1 IFN induction play a role in the amelioration of EAE. Moreover, Amylin 28-33, a polar, non-ionizable peptide that does not form fibrils as rapidly as Tau 623-628, induces a small fraction of type 1 IFN compared to Tau 623-628 and is therapeutic in Th17 EAE. The diverse immunological pathways modulated by the self-assembling hexapeptides are under investigation with a goal to develop novel, safe, and potent therapeutics for neuroinflammation.

Abstract

Along with their established role in allergic reactions, histamine and its receptors have been implicated in the pathology of multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis. In this study we analyzed the gene expression of histamine receptor 1 (HRH1), HRH2 and HRH4 in peripheral blood mononuclear cells derived from patients with clinically isolated syndrome (CIS), relapsing-remitting (RR) MS, secondary-progressive (SP) MS, primary-progressive (PP) MS, and healthy controls (HC). We found that HRH1 transcript was significantly down-modulated in SP-MS compared with HC, and HRH4 was increased in this group compared to HC, CIS and RR-MS. No other differences in the expression of histamine receptors were observed between HC, CIS and other clinical forms of definite MS.

From defining antigens to new therapies in multiple sclerosis: Honoring the contributions of Ruth Arnon and Michael SelaJOURNAL OF AUTOIMMUNITYSteinman, L., Shoenfeld, Y.2014; 54: 1-7

Abstract

Ruth Arnon and Michael Sela profoundly influenced the development of a model system to test new therapies in multiple sclerosis (MS). Their application of the animal model, known as experimental autoimmune encephalomyelitis (EAE), for the discovery of Copaxone, opened a new path for testing of drug candidates in MS. By measuring clinical, pathologic, and immunologic outcomes, the biological implications of new drugs could be elucidated. Using EAE they established the efficacy of Copaxone as a therapy for preventing and reducing paralysis and inflammation in the central nervous system without massive immune suppression. This had a huge impact on the field of drug discovery for MS. Much like the use of parabiosis to discover soluble factors associated with obesity, or the replica plating system to probe antibiotic resistance in bacteria, the pioneering research on Copaxone using the EAE model, paved the way for the discovery of other therapeutics in MS, including Natalizumab and Fingolimod. Future applications of this approach may well elucidate novel therapies for the neurodegenerative phase of multiple sclerosis associated with disease progression.

Abstract

Immunologists are well aware that cancer regression and increased patient survival with the use of checkpoint inhibitors, such as ipilimumab, an antibody directed against cytotoxic T-lymphocyte-associated antigen 4, CTLA-4 (CD152), is accompanied by concomitant autoimmunity. For over 30 years, a small group of investigators have shown that the rare paraneoplastic syndromes are caused by immunity to shared antigens found on both tumors and on components of the nervous system. In this issue of the European Journal of Immunology, Blachère et al. [Eur. J. Immunol. 2014. 44: 3240-3251] elucidate some of the molecular mechanisms underlying the tolerance to neuronal antigens which share epitopes with oncologic antigens, observed in the context of paraneoplastic syndromes in mice. The presence of the shared tumor antigen on a nonhematopoietic cell underlies the basis for a certain level of tolerance in CD4+ and CD8+ T cells, preventing these cells from attacking the brain, but allowing them to lyse the tumor upon transfer into tumor-bearing recipient mice. Comparisons between the paraneoplastic syndromes and the new autoimmune conditions seen with antibodies to immune checkpoints at CD152 or at CD279 are likely to illuminate shared mechanisms and solutions to these vexing diseases.

Abstract

The immune system plays a major role in certain diseases of the brain like multiple sclerosis and neuromyelitis optica, while the brain may play a major role in modulating certain immunologic diseases of the periphery like inflammatory bowel disease. The most significant developments in neuroimmunology will involve explorations of the roles for the immune system in neurodegenerative conditions often associated with the presence of amyloid deposits. Here I present my personal perspectives on four of the most intriguing challenges that we face in the future of neuroimmunology: (1) Why are the traditional hallmarks of innate and adaptive inflammation conspicuously absent from brains of individuals with prion disease and amyloid pathology? (2) What is the role of adaptive and innate immunity in progressive forms of multiple sclerosis? (3) Is molecular mimicry an adequate explanation for the initiation of neuroinflammatory disease and for exacerbations in conditions like multiple sclerosis, narcolepsy, and neuromyelitis optica? (4) Do neural pathways regulate inflammatory diseases outside the nervous system?

Abstract

The NOD mouse strain spontaneously develops autoimmune diabetes. A deficiency in costimulatory molecules, such as B7-2, on the NOD genetic background prevents diabetes but instead triggers an inflammatory peripheral neuropathy. This constitutes a shift in the target of autoimmunity, but the underlying mechanism remains unknown. In this study, we demonstrate that NOD mice deficient for isoforms of ICAM-1, which comediate costimulatory functions, spontaneously develop a chronic autoimmune peripheral neuritis instead of diabetes. The disease is transferred by CD4(+) T cells, which infiltrate peripheral nerves together with macrophages and B cells and are autoreactive against peripheral myelin protein zero. These Icam1(tm1Jcgr)NOD mice exhibit unaltered numbers of regulatory T cells, but increased IL-17-producing T cells, which determine the severity, but not the target specificity, of autoimmunity. Ab-mediated ICAM-1 blockade triggers neuritis only in young NOD mice. Thymic epithelium from Icam1(tm1Jcgr)NOD mice features an altered expression of costimulatory molecules and induces neuritis and myelin autoreactivity after transplantation into nude mice in vivo. Icam1(tm1Jcgr)NOD mice exhibit a specifically altered TCR repertoire. Our findings introduce a novel animal model of chronic inflammatory neuropathies and indicate that altered expression of ICAM-1 on thymic epithelium shifts autoimmunity specifically toward peripheral nerves. This improves our understanding of autoimmunity in the peripheral nervous system with potential relevance for human diseases.

Abstract

To elucidate immunopathogenetic roles of aquaporin-4 antibodies in the cerebrospinal fluid (CSF) of neuromyelitis optica spectrum disorders (NMOSD), we analyzed aquaporin-4 antibody titers, cellular and inflammatory markers in the CSF collected from 11 aquaporin-4 antibody seropositive patients. The CSF aquaporin-4 antibody levels during attacks (but not in sera) closely correlated with pleocytosis, inflammatory cytokines including interleukin-6 that can regulate antibody-producing plasmablasts, and glial fibrillary acidic protein levels in the CSF. The amount of aquaporin-4 antibodies present in the central nervous system may have therapeutic implications, as it is associated with astrocyte injury and inflammatory responses during NMOSD attacks.

Abstract

Amyloid forming molecules are generally considered harmful. In Alzheimer's Disease two amyloid molecules Aβ A4 and tau vie for consideration as the main pathogenic culprit. But molecules obey the laws of chemistry and defy the way we categorize them as humans with our well-known proclivities to bias in our reasoning. We have been exploring the brains of multiple sclerosis patients to identify molecules that are associated with protection from inflammation and degeneration. In 2001 we noted that aB crystallin (cryab) was the most abundant transcript found in MS lesions, but not in healthy brains. Cryab can reverse paralysis and attenuate inflammation in several models of inflammation including experimental autoimmune encephalomyelitis (EAE), and various models of ischemia. Cryab is an amyloid forming molecule. We have identified a core structure common to many amyloids including amyloid protein Aβ A4, tau, amylin, prion protein, serum amyloid protein P, and cryab. The core hexapeptide structure is highly immune suppressive and can reverse paralysis in EAE when administered systemically. Administration of this amyloid forming hexapeptide quickly lowers inflammatory cytokines in plasma like IL-6 and IL-2. The hexapeptide bind a set of proinflammatory mediators in plasma, including acute phase reactants and complement components. The beneficial properties of amyloid forming hexapeptides provide a potential new therapeutic direction. These experiments indicate that amyloid forming molecules have Janus faces, providing unexpected benefit for neuroinflammatory conditions.

Abstract

Amyloid forming molecules are generally considered harmful. In Alzheimer's Disease two amyloid molecules Aβ A4 and tau vie for consideration as the main pathogenic culprit. But molecules obey the laws of chemistry and defy the way we categorize them as humans with our well-known proclivities to bias in our reasoning. We have been exploring the brains of multiple sclerosis patients to identify molecules that are associated with protection from inflammation and degeneration. In 2001 we noted that aB crystallin (cryab) was the most abundant transcript found in MS lesions, but not in healthy brains. Cryab can reverse paralysis and attenuate inflammation in several models of inflammation including experimental autoimmune encephalomyelitis (EAE), and various models of ischemia. Cryab is an amyloid forming molecule. We have identified a core structure common to many amyloids including amyloid protein Aβ A4, tau, amylin, prion protein, serum amyloid protein P, and cryab. The core hexapeptide structure is highly immune suppressive and can reverse paralysis in EAE when administered systemically. Administration of this amyloid forming hexapeptide quickly lowers inflammatory cytokines in plasma like IL-6 and IL-2. The hexapeptide bind a set of proinflammatory mediators in plasma, including acute phase reactants and complement components. The beneficial properties of amyloid forming hexapeptides provide a potential new therapeutic direction. These experiments indicate that amyloid forming molecules have Janus faces, providing unexpected benefit for neuroinflammatory conditions.

Narcolepsy, 2009 A(H1N1) pandemic influenza, and pandemic influenza vaccinations: What is known and unknown about the neurological disorder, the role for autoimmunity, and vaccine adjuvantsJOURNAL OF AUTOIMMUNITYAhmed, S. S., Schur, P. H., MacDonald, N. E., Steinman, L.2014; 50: 1-11

Abstract

The vaccine safety surveillance system effectively detected a very rare adverse event, narcolepsy, in subjects receiving AS03-adjuvanted A(H1N1) pandemic vaccine made using the European inactivation/purification protocol. The reports of increased cases of narcolepsy in non-vaccinated subjects infected with wild A(H1N1) pandemic influenza virus suggest a role for the viral antigen(s) in disease development. However, additional investigations are needed to better understand what factor(s) in wild influenza infection trigger(s) narcolepsy in susceptible hosts. An estimated 31 million doses of European AS03-adjuvanted A(H1N1) pandemic vaccine were used in more than 47 countries. The Canadian AS03-adjuvanted A(H1N1) pandemic vaccine was used with high coverage in Canada where an estimated 12 million doses were administered. As no similar narcolepsy association has been reported to date with the AS03-adjuvanted A(H1N1) pandemic vaccine made using the Canadian inactivation/purification protocol, this suggests that the AS03 adjuvant alone may not be responsible for the narcolepsy association. To date, no narcolepsy association has been reported with the MF59®-adjuvanted A(H1N1) pandemic vaccine. This review article provides a brief background on narcolepsy, outlines the different types of vaccine preparations including the ones for influenza, reviews the accumulated evidence for the safety of adjuvants, and explores the association between autoimmune diseases and natural infections. It concludes by assimilating the historical observations and recent clinical studies to formulate a feasible hypothesis on why vaccine-associated narcolepsy may not be solely linked to the AS03 adjuvant but more likely be linked to how the specific influenza antigen component of the European AS03-adjuvanted pandemic vaccine was prepared. Careful and long-term epidemiological studies of subjects who developed narcolepsy in association with AS03-adjuvanted A(H1N1) pandemic vaccine prepared with the European inactivation/purification protocol are needed.

Abstract

Using an integrated antigen microarray approach, we observed epitope-spreading of autoantibody responses to a variety of antigenic structures in the cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS) and in the serum of mice with experimental autoimmune encephalomyelitis (EAE). These included previously described protein- and lipid-based antigenic targets and newly discovered autoimmunogenic sugar moieties, notably, autoantibodies specific for the oligomannoses in both MS patient CSF and the sera of mice with EAE. These glycans are often masked by other sugar moieties and belong to a class of cryptic autoantigens. We further determined that these targets are highly expressed on multiple cell types in MS and EAE lesions. Co-immunization of SJL/J mice with a Man9-KLH conjugate at the time of EAE induction elicited highly significant levels of anti-Man9-cluster autoantibodies. Nevertheless, this anti-glycan autoantibody response was associated with a significantly reduced clinical severity of EAE. The potential of these cryptic glycan markers and targeting antibodies for diagnostic and therapeutic interventions of neurological disorders has yet to be explored.

Development of therapies for autoimmune disease at Stanford: a tale of multiple shots and one goalIMMUNOLOGIC RESEARCHSteinman, L.2014; 58 (2-3): 307-314

Abstract

The title of this contribution on Immunology at Stanford is purposely ambiguous. One goal is the development of safe and effective therapy for autoimmune diseases. Another definition of goal is to score, and this would ultimately mean the development of an approved drug. Indeed, the efforts in my four decades at Stanford, have included the discovery and subsequent development of a monoclonal antibody to block homing to the inflamed brain, leading to natalizumab, an approved therapeutic for two autoimmune diseases: relapsing-remitting MS and for inflammatory bowel disease. Multiple attempts to develop new therapies for autoimmune disease are described here: The trimolecular complex and the immune synapse serve as one major set of targets, with attempts to inhibit particular major histocompatibility molecules, the variable regions of the T cell receptor, and CD4. Other approaches focusing on antigen-specific tolerance include ongoing attempts with tolerizing DNA vaccines in type 1 diabetes. Finally, the repurposing of popular drugs approved for other indications, including statins and inhibitors of angiotensin converting enzyme is under development and showing promise in the clinic, particularly for secondary progressive multiple sclerosis. The milieu within Stanford Immunology has helped to nurture these efforts to translate discoveries in immunology and to take them from bench to bedside.

Abstract

Aberrant microglial responses contribute to neuroinflammation in many neurodegenerative diseases, but no current therapies target pathogenic microglia. We discovered unexpectedly that the antiviral drug ganciclovir (GCV) inhibits the proliferation of microglia in experimental autoimmune encephalomyelitis (EAE), a mouse model for multiple sclerosis (MS), as well as in kainic acid-induced excitotoxicity. In EAE, GCV largely prevented infiltration of T lymphocytes into the central nervous system (CNS) and drastically reduced disease incidence and severity when delivered before the onset of disease. In contrast, GCV treatment had minimal effects on peripheral leukocyte distribution in EAE and did not inhibit generation of antibodies after immunization with ovalbumin. Additionally, a radiolabeled analogue of penciclovir, [(18)F]FHBG, which is similar in structure to GCV, was retained in areas of CNS inflammation in EAE, but not in naive control mice, consistent with the observed therapeutic effects. Our experiments suggest GCV may have beneficial effects in the CNS beyond its antiviral properties.

Abstract

Oral atorvastatin has prevented or reversed paralysis in the multiple sclerosis (MS) model experimental autoimmune encephalomyelitis (EAE), and reduced development of new MS lesions in clinical trials. Besides inhibiting development of encephalitogenic T cells, atorvastatin treatment of EAE has been associated with an induction of anti-inflammatory myelin-reactive T-helper type (Th)-2 cells. To investigate the clinical significance of atorvastatin-mediated Th2 differentiation, we first evaluated atorvastatin treatment in interleukin (IL)-4 green fluorescent protein-enhanced transcript (4-GET) reporter mice. Atorvastatin treatment failed to induce IL-4-producing Th2 cells in vivo; however, when T cells from atorvastatin-treated 4-GET mice were reactivated in vitro, T cells preferentially differentiated into Th2 cells, while antigen-specific T-cell proliferation and secretion of proinflammatory cytokines (interferon gamma, IL-17, tumor necrosis factor and IL-12) were reduced. Oral atorvastatin also prevented or reversed EAE in signal transducer and activator of transcription 6-deficient (STAT6-/-) mice, which cannot generate IL-4-producing Th2 cells. Further, atorvastatin treatment did not induce or expand Foxp3+ regulatory T cells in either wild-type or STAT6-/- mice. In vivo proliferation of T cells, as measured by incorporation of bromodeoxyuridine, was inhibited in atorvastatin-treated wild-type and STAT6-/- mice. These data imply that atorvastatin ameliorates central nervous system autoimmune disease primarily by inhibiting proliferation of proinflammatory encephalitogenic T cells, and not simply through induction of anti-inflammatory Th2 cells. This cytostatic effect may be a relevant mechanism of action when considering use of statins in MS and other inflammatory conditions.

Abstract

Metabolic stroke is the rapid onset of lasting central neurological deficit associated with decompensation of an underlying metabolic disorder. Glutaric aciduria type I (GA1) is an inherited disorder of lysine and tryptophan metabolism presenting with metabolic stroke in infancy. The clinical presentation includes bilateral striatal necrosis and spontaneous subdural and retinal hemorrhages, which has been frequently misdiagnosed as non-accidental head trauma. The mechanisms underlying metabolic stroke and spontaneous hemorrhage are poorly understood.Using a mouse model of GA1, we show that metabolic stroke progresses in the opposite sequence of ischemic stroke, with initial neuronal swelling and vacuole formation leading to cerebral capillary occlusion. Focal regions of cortical followed by striatal capillaries are occluded with shunting to larger non-exchange vessels leading to early filling and dilation of deep cerebral veins. Blood-brain barrier breakdown was associated with displacement of tight-junction protein Occludin.Together the current findings illuminate the pathophysiology of metabolic stroke and vascular compromise in GA1, which may translate to other neurometabolic disorders presenting with stroke.

Abstract

BACKGROUND: Suppression of activation of pathogenic CD4(+) T cells is a potential therapeutic intervention in multiple sclerosis (MS). We previously showed that a small heat shock protein, CRYAB, reduced T cell proliferation, pro-inflammatory cytokine production and clinical signs of experimental allergic encephalomyelitis, a model of MS. OBJECTIVE: We assessed whether the ability of CRYAB to reduce the activation of T cells translated to the human disease. METHODS: CD4(+) T cells from healthy controls and volunteers with MS were activated in vitro in the presence or absence of a CRYAB peptide (residues 73-92). Parameters of activation (proliferation rate, cytokine secretion) and tolerance (anergy, activation-induced cell death, microRNAs) were evaluated. RESULTS: The secretion of pro-inflammatory cytokines by CD4(+) T cells was decreased in the presence of CRYAB in a subset of relapsing-remitting multiple sclerosis (RRMS) participants with mild disease severity while no changes were observed in healthy controls. Further, there was a correlation for higher levels of miR181a microRNA, a marker upregulated in tolerant CD8(+) T cells, in CD4(+) T cells of MS patients that displayed suppressed cytokine production (responders). CONCLUSION: CRYAB may be capable of suppressing the activation of CD4(+) T cells from a subset of RRMS patients who appear to have less disability but similar age and disease duration.

Abstract

Some clinical trials in humans have aimed at modulation of type 1 diabetes (T1D) via alteration of the immune response to putative islet cell antigens, particularly proinsulin and insulin, glutamic acid decarboxylase and the peptide, DiaPep 277, derived from heat shock protein 60. The focus here is on development of a specially engineered DNA plasmid encoding proinsulin to treat T1D. The plasmid is engineered to turn off adaptive immunity to proinsulin. This approach yielded exciting results in a randomized placebo controlled trial in 80 adult patients with T1D. The implications of this trial are explored in regards to the potential for sparing inflammation in islets and thus allowing the functioning beta cells to recover and produce more insulin. Strategies to further strengthen the effects seen thus far with the tolerizing DNA plasmid to proinsulin will be elucidated. The DNA platform affords an opportunity for easy modifications. In addition standard exploration of dose levels, route of administration and frequency of dose are practical. Optimization of the effects seen to date on C-peptide and on depletion of proinsulin specific CD8 T cells are feasible, with expected concomitant improvement in other parameters like hemoglobin A1c and reduction in insulin usage. T1D is one of the few autoimmune conditions where antigen specific therapy can be achieved, provided the approach is tested intelligently. Tolerizing DNA vaccines to proinsulin and other islet cell autoantigens is a worthy pursuit to potentially treat, prevent and to perhaps even 'cure' or 'prevent' type 1 diabetes.

Abstract

Several innovative disease-modifying treatments (DMTs) for relapsing-remitting multiple sclerosis have been licensed recently or are in late-stage development. The molecular targets of several of these DMTs are well defined. All affect at least 1 of 4 properties, namely (1) trafficking, (2) survival, (3) function, or (4) proliferation. In contrast to β-interferons and glatiramer acetate, the first-generation DMTs, several newer therapies are imbued with safety issues, which may be attributed to their structure or metabolism. In addition to efficacy, understanding the relationship between the mechanism of action of the DMTs and their safety profile is pertinent for decision making and patient care. In this article, we focus primarily on the safety of DMTs in the context of understanding their pharmacological characteristics, including molecular targets, mechanism of action, chemical structure, and metabolism. While understanding mechanisms underlying DMT toxicities is incomplete, it is important to further develop this knowledge to minimize risk to patients and to ensure future therapies have the most advantageous benefit-risk profiles. Recognizing the individual classes of DMTs described here may be valuable when considering use of such agents sequentially or possibly in combination.

Abstract

Several innovative disease-modifying treatments (DMTs) for relapsing-remitting multiple sclerosis have been licensed recently or are in late-stage development. The molecular targets of several of these DMTs are well defined. All affect at least 1 of 4 properties, namely (1) trafficking, (2) survival, (3) function, or (4) proliferation. In contrast to β-interferons and glatiramer acetate, the first-generation DMTs, several newer therapies are imbued with safety issues, which may be attributed to their structure or metabolism. In addition to efficacy, understanding the relationship between the mechanism of action of the DMTs and their safety profile is pertinent for decision making and patient care. In this article, we focus primarily on the safety of DMTs in the context of understanding their pharmacological characteristics, including molecular targets, mechanism of action, chemical structure, and metabolism. While understanding mechanisms underlying DMT toxicities is incomplete, it is important to further develop this knowledge to minimize risk to patients and to ensure future therapies have the most advantageous benefit-risk profiles. Recognizing the individual classes of DMTs described here may be valuable when considering use of such agents sequentially or possibly in combination.

Abstract

Type I IFNs (IFN-α and IFN-β) and type II IFN (IFN-γ) mediate both regulation and inflammation in multiple sclerosis, neuromyelitis optica, and in experimental autoimmune encephalomyelitis (EAE). However, the underlying mechanism for these Janus-like activities of type I and II IFNs in neuroinflammation remains unclear. Although endogenous type I IFN signaling provides a protective response in neuroinflammation, we find that when IFN-γ signaling is ablated, type I IFNs drive inflammation, resulting in exacerbated EAE. IFN-γ has a disease stage-specific opposing function in EAE. Treatment of mice with IFN-γ during the initiation phase of EAE leads to enhanced severity of disease. In contrast, IFN-γ treatment during the effector phase attenuated disease. This immunosuppressive activity of IFN-γ required functional type I IFN signaling. In IFN-α/β receptor-deficient mice, IFN-γ treatment during effector phase of EAE exacerbated disease. Using an adoptive transfer EAE model, we found that T cell-intrinsic type I and II IFN signals are simultaneously required to establish chronic EAE by encephalitogenic Th1 cells. However, in Th17 cells loss of either IFN signals leads to the development of a severe chronic disease. The data imply that type I and II IFN signals have independent but nonredundant roles in restraining encephalitogenic Th17 cells in vivo. Collectively, our data show that type I and II IFNs function in an integrated manner to regulate pathogenesis in EAE.

Abstract

IMPORTANCE High serum levels of interleukin 17F (IL-17F) at baseline have been associated with suboptimal response to interferon beta in patients with relapsing-remitting multiple sclerosis. OBJECTIVE To further investigate the role of IL-17F in predicting treatment response to interferon beta-1b in patients with relapsing-remitting multiple sclerosis using the Singulex Erenna IL-17F immunoassay. DESIGN, SETTING, AND PATIENTS Serum samples were analyzed from 239 randomly selected patients treated with interferon beta-1b, 250 μg, for at least 2 years in the Betaferon Efficacy Yielding Outcomes of a New Dose Study. EXPOSURE Treatment with interferon beta-1b, 250 μg, for at least 2 years. MAIN OUTCOME MEASURES Levels of IL-17F at baseline and month 6 as well as the difference between the IL-17F levels at month 6 and baseline were compared between the following: (1) patients with less disease activity vs more disease activity; (2) patients with no disease activity vs some disease activity; and (3) responders vs nonresponders. RESULTS Levels of IL-17F measured at baseline and month 6 did not correlate with lack of response to treatment after 2 years using clinical and magnetic resonance imaging criteria. Relapses and new lesions on magnetic resonance imaging were not associated with pretreatment serum IL-17F levels. When patients with neutralizing antibodies were excluded, the results did not change. All patients with levels of IL-17F greater than 200 pg/mL were associated with poor response with some clinical or radiological activity. CONCLUSIONS AND RELEVANCE An increase of IL-17F before and early after treatment with interferon beta-1b was not associated with poor response. These data do not support the value of IL-17F as a treatment response indicator for therapy of patients with multiple sclerosis with interferon beta, although high levels of IL-17F greater than 200 pg/mL may predict nonresponsiveness.

Abstract

In chronically inflamed tissues, such as those affected by autoimmune disease, activated Th cells often colocalize with monocytes. We investigate in this study how murine Th cells influence the phenotype and function of monocytes. The data demonstrate that Th1, Th2, and Th17 subsets promote the differentiation of autologous monocytes into MHC class II(+), CD11b(+), CD11c(+) DC that we call DCTh. Although all Th subsets induce the formation of DCTh, activated Th17 cells uniquely promote the formation of IL-12/IL-23-producing DCTh (DCTh17) that can polarize both naive and Th17 cells to a Th1 phenotype. In the inflamed CNS of mice with Th17-mediated experimental autoimmune encephalomyelitis, Th cells colocalize with DC, as well as monocytes, and the Th cells obtained from these lesions drive the formation of DCTh that are phenotypically indistinguishable from DCTh17 and polarize naive T cells toward a Th1 phenotype. These results suggest that DCTh17 are critical in the interplay of Th17- and Th1-mediated responses and may explain the previous finding that IL-17-secreting Th cells become IFN-γ-secreting Th1 cells in experimental autoimmune encephalomyelitis and other autoimmune disorders.

Abstract

Oligodendrocytes-the myelin-forming cells of the central nervous system-can be regenerated during adulthood. In adults, new oligodendrocytes originate from oligodendrocyte progenitor cells (OPCs), but also from neural stem cells (NSCs). Although several factors supporting oligodendrocyte production have been characterized, the mechanisms underlying the generation of adult oligodendrocytes are largely unknown. Here we show that genetic inactivation of SIRT1, a protein deacetylase implicated in energy metabolism, increases the production of new OPCs in the adult mouse brain, in part by acting in NSCs. New OPCs produced following SIRT1 inactivation differentiate normally, generating fully myelinating oligodendrocytes. Remarkably, SIRT1 inactivation ameliorates remyelination and delays paralysis in mouse models of demyelinating injuries. SIRT1 inactivation leads to the upregulation of genes involved in cell metabolism and growth factor signalling, in particular PDGF receptor α (PDGFRα). Oligodendrocyte expansion following SIRT1 inactivation is mediated at least in part by AKT and p38 MAPK-signalling molecules downstream of PDGFRα. The identification of drug-targetable enzymes that regulate oligodendrocyte regeneration in adults could facilitate the development of therapies for demyelinating injuries and diseases, such as multiple sclerosis.

Abstract

In relapsing remitting multiple sclerosis (RRMS), type I interferon (IFN) is considered immuno-modulatory, and recombinant forms of IFN-β are the most prescribed treatment for this disease. However, within the RRMS population, 30-50% of MS patients are nonresponsive to this treatment, and it consistently worsens neuromyelitis optica (NMO), a disease once considered to be a form of RRMS. In contrast to RRMS, type I IFNs have been shown to have properties that drive the inflammatory pathologies in many other autoimmune diseases. These diseases include Sjögren's syndrome, system lupus erythematosus (SLE), neuromyelitis optica (NMO), rheumatoid arthritis (RA) and psoriasis. Historically, autoimmune diseases were thought to be driven by a TH1 response to auto-antigens. However, since the discovery of the TH17 in experimental autoimmune encephalomyelitis (EAE), it is now generally thought that TH17 plays an important role in MS and all other autoimmune diseases. In this article, we will discuss recent clinical and basic research advances in the field of autoimmunity and argue that IFN-β and other type I IFNs are immuno-modulatory in diseases driven predominantly by TH1 but in contrast are inflammatory in diseases that have a predominant Th17 response.

Abstract

A recent type 1 diabetes (T1D) clinical trial of rituximab (a B cell-depleting anti-CD20 antibody) achieved some therapeutic benefit in preserving C-peptide for a period of approximately nine months in patients with recently diagnosed diabetes. Our previous data in the NOD mouse demonstrated that co-administration of antigen (insulin) with anti-CD3 antibody (a T cell-directed immunomodulator) offers better protection than either entity alone, indicating that novel combination therapies that include a T1D-related autoantigen are possible. To accelerate the identification and development of novel combination therapies that can be advanced into the clinic, we have evaluated the combination of a mouse anti-CD20 antibody with either oral insulin or a proinsulin-expressing DNA vaccine. Anti-CD20 alone, given once or on 4 consecutive days, produced transient B cell depletion but did not prevent or reverse T1D in the NOD mouse. Oral insulin alone (twice weekly for 6 weeks) was also ineffective, while proinsulin DNA (weekly for up to 12 weeks) showed a trend toward modest efficacy. Combination of anti-CD20 with oral insulin was ineffective in reversing diabetes in NOD mice whose glycemia was controlled with SC insulin pellets; these experiments were performed in three independent labs. Combination of anti-CD20 with proinsulin DNA was also ineffective in diabetes reversal, but did show modest efficacy in diabetes prevention (p = 0.04). In the prevention studies, anti-CD20 plus proinsulin resulted in modest increases in Tregs in pancreatic lymph nodes and elevated levels of proinsulin-specific CD4+ T-cells that produced IL-4. Thus, combination therapy with anti-CD20 and either oral insulin or proinsulin does not protect hyperglycemic NOD mice, but the combination with proinsulin offers limited efficacy in T1D prevention, potentially by augmentation of proinsulin-specific IL-4 production.

Abstract

Natalizumab has been available as a multiple sclerosis treatment for more than 5 years in Europe and the United States. Natalizumab was granted approval by the US Food and Drug Administration in 2004, only 12 years after its molecular target was cloned. Shortly after initial approval, natalizumab use was suspended pending a safety review when several natalizumab recipients were diagnosed as having progressive multifocal leukoencephalopathy. After the safety review, natalizumab was reintroduced to the market in 2006. Since then, more than 92,000 patients have been treated with the drug. Risk stratification algorithms and progressive multifocal leukoencephalopathy management strategies have been developed, which facilitate more personalized decision making and safer natalizumab use. This review article summarizes the evolution of natalizumab from target molecule discovery through regulatory approval, voluntary suspension, reapproval, and clinical use. The natalizumab story highlights both the opportunities and risks inherent in a novel biological therapy for a progressive neurologic disease.

Abstract

There is a significant unmet need for serum biomarkers in relapsing-remitting multiple sclerosis (RRMS) that are predictive of therapeutic response to disease-modifying therapies. Following a recent Stanford study which reported that pretreatment levels of serum interleukin (IL)-17F could predict poor response to interferon-β (IFNβ) therapy, we sought to validate the finding using samples from a large clinical trial.The validation cohort included 54 good responders (GR) and 64 poor responders (PR) selected from 762 subjects with RRMS from the IM IFNβ-1a dose comparison study (Avonex study C94-805). Subjects were classified as GR and PR based on the number of relapses, Expanded Disability Status Scale score, and new and enlarging T2 lesions on MRI. Serum samples were assayed for IL-17F using a multiplexed Luminex assay and for IL-17F/F using an ELISA. Replicate aliquots from the Stanford study were also assayed to assure reproducibility of methods.Median pretreatment and post-treatment serum IL-17F levels were not statistically significantly different between GR and PR, and serum IL-7/IL-17F ratios were also not predictive of response status. Replicate aliquots from the Stanford study showed good correlation to their original cohort (r = 0.77).We were unable to validate the finding that serum IL-17F is a predictor of PR in a large independent cohort of subjects with RRMS. Differences in patient populations and methodology might explain the failure to validate the results from the Stanford study.

Lessons learned at the intersection of immunology and neuroscienceJOURNAL OF CLINICAL INVESTIGATIONSteinman, L.2012; 122 (4): 1146-1148

Abstract

Neurobiologists and immunologists study concepts often signified with identical terminology. Scientists in both fields study a structure known as the synapse, and each group analyzes a subject called memory. Is this a quirk of human language, or are there real similarities between these two physiological systems? Not only are the linguistic concepts expressed in the words "synapse" and "memory" shared between the fields, but the actual molecules of physiologic importance in one system play parallel roles in the other: complement, the major histocompatibility molecules, and even "neuro"-transmitters all have major impacts on health and on disease in both the brain and the immune system. Not only are the same molecules found in diverse roles in each system, but we have learned that there is real "hard-wired" crosstalk between nerves and lymphoid organs. This issue of the JCI highlights some of the lessons learned from experts who are working at this scintillating intersection between immunology and neuroscience.

Abstract

Historically, small heat shock proteins (sHSPs) have been extensively studied in the context of being intracellular molecular chaperones. However, recent studies looking at the role of sHSPs in neurological diseases have demonstrated a near universal upregulation of certain sHSPs in damaged and diseased brains. Initially, it was thought that sHSPs are pathological in these disease states because they are found in the areas of damage. However, transgenic overexpression and exogenous administration of sHSPs in various experimental disease paradigms have shown just the contrary - that sHSPs are protective, not pathological. This review examines sHSPs in neurological diseases and highlights the potential for using these neuroprotective sHSPs as novel therapeutics. It first addresses the endogenous expression of sHSPs in a variety of neurological disorders. Although many studies have examined the expression of sHSPs in neurological diseases, there are no review articles summarizing these data. Furthermore, it focuses on recent studies that have investigated the therapeutic potential of sHSPs for neurological diseases. Finally, it will explain what we think is the function of endogenous sHSPs in neurological diseases.

Abstract

Historically, small heat shock proteins (sHSPs) have been extensively studied in the context of being intracellular molecular chaperones. However, recent studies looking at the role of sHSPs in neurological diseases have demonstrated a near universal upregulation of certain sHSPs in damaged and diseased brains. Initially, it was thought that sHSPs are pathological in these disease states because they are found in the areas of damage. However, transgenic overexpression and exogenous administration of sHSPs in various experimental disease paradigms have shown just the contrary - that sHSPs are protective, not pathological. This review examines sHSPs in neurological diseases and highlights the potential for using these neuroprotective sHSPs as novel therapeutics. It first addresses the endogenous expression of sHSPs in a variety of neurological disorders. Although many studies have examined the expression of sHSPs in neurological diseases, there are no review articles summarizing these data. Furthermore, it focuses on recent studies that have investigated the therapeutic potential of sHSPs for neurological diseases. Finally, it will explain what we think is the function of endogenous sHSPs in neurological diseases.

Abstract

Multiple sclerosis is an autoimmune disease of the central nervous system characterized by neuroinflammation and demyelination. Although considered a T cell-mediated disease, multiple sclerosis involves the activation of both adaptive and innate immune cells, as well as resident cells of the central nervous system, which synergize in inducing inflammation and thereby demyelination. Differentiation, survival, and inflammatory functions of innate immune cells and of astrocytes of the central nervous system are regulated by tyrosine kinases. Here, we show that imatinib, sorafenib, and GW2580-small molecule tyrosine kinase inhibitors-can each prevent the development of disease and treat established disease in a mouse model of multiple sclerosis. In vitro, imatinib and sorafenib inhibited astrocyte proliferation mediated by the tyrosine kinase platelet-derived growth factor receptor (PDGFR), whereas GW2580 and sorafenib inhibited macrophage tumor necrosis factor (TNF) production mediated by the tyrosine kinases c-Fms and PDGFR, respectively. In vivo, amelioration of disease by GW2580 was associated with a reduction in the proportion of macrophages and T cells in the CNS infiltrate, as well as a reduction in the levels of circulating TNF. Our findings suggest that GW2580 and the FDA-approved drugs imatinib and sorafenib have potential as novel therapeutics for the treatment of autoimmune demyelinating disease.

Abstract

A new class of inflammatory CD4(+) T cells that produce interleukin-17 (IL-17) (termed Th17) has been identified, which plays a critical role in numerous inflammatory conditions and autoimmune diseases. The active form of vitamin D, 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)], has a direct repressive effect on the expression of IL-17A in both human and mouse T cells. In vivo treatment of mice with ongoing experimental autoimmune encephalomyelitis (EAE; a mouse model of multiple sclerosis) diminishes paralysis and progression of the disease and reduces IL-17A-secreting CD4(+) T cells in the periphery and central nervous system (CNS). The mechanism of 1,25(OH)(2)D(3) repression of IL-17A expression was found to be transcriptional repression, mediated by the vitamin D receptor (VDR). Transcription assays, gel shifting, and chromatin immunoprecipitation (ChIP) assays indicate that the negative effect of 1,25(OH)(2)D(3) on IL-17A involves blocking of nuclear factor for activated T cells (NFAT), recruitment of histone deacetylase (HDAC), sequestration of Runt-related transcription factor 1 (Runx1) by 1,25(OH)(2)D(3)/VDR, and a direct effect of 1,25(OH)(2)D(3) on induction of Foxp3. Our results describe novel mechanisms and new concepts with regard to vitamin D and the immune system and suggest therapeutic targets for the control of autoimmune diseases.

Abstract

The interleukin-7 receptor α chain (IL-7Rα) gene was identified as a top non-major histocompatibility complex-linked risk locus for multiple sclerosis (MS). Recently, we showed that a T helper 1 (T(H)1)-driven, but not a T(H)17-driven, form of MS exhibited a good clinical response to interferon-β (IFN-β) therapy. We now demonstrate that high serum levels of IL-7, particularly when paired with low levels of IL-17F, predict responsiveness to IFN-β and hence a T(H)1-driven subtype of MS. We also show that although IL-7 signaling is neither necessary nor sufficient for the induction or expansion of T(H)17 cells, IL-7 can greatly enhance both human and mouse T(H)1 cell differentiation. IL-7 alone is sufficient to induce human T(H)1 differentiation in the absence of IL-12 or other cytokines. Furthermore, targeting IL-7/IL-7Rα is beneficial in experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. Mice treated with IL-7Rα-blocking antibodies before or after onset of paralysis exhibited reduced clinical signs of EAE, with reduction in peripheral naïve and activated T cells, whereas central memory T, regulatory T, B, and natural killer cell populations were largely spared. IL-7Rα antibody treatment markedly reduced lymphocyte infiltration into the central nervous system in mice with EAE. Thus, a serum profile of high IL-7 may signify a T(H)1-driven form of MS and may predict outcome in MS patients undergoing IFN-β therapy. Blockade of IL-7 and the IL-7Rα pathway may have therapeutic potential in MS and other autoimmune diseases.

Abstract

To determine whether low levels of 25-hydroxyvitamin D (25[OH]D) contribute to the increased risk of postpartum multiple sclerosis (MS) relapses.Prospective cohort study.Outpatients identified through membership records of Kaiser Permanente Northern California or Stanford University outpatient neurology clinics.Twenty-eight pregnant women with MS.We prospectively followed up patients through the postpartum year and assessed exposures and symptoms through structured interviews. Total serum 25(OH)D levels were measured using the DiaSorin Liaison Assay during the third trimester and 2, 4, and 6 months after giving birth. The data were analyzed using longitudinal multivariable methods.Levels of 25(OH)D and relapse rate.Fourteen (50%) women breastfed exclusively, and 12 women (43%) relapsed within 6 months after giving birth. During pregnancy, the average 25(OH)D levels were 25.4 ng/mL (range, 13.7-42.6) and were affected only by season (P=.009). In contrast, in the postpartum period, 25(OH)D levels were significantly affected by breastfeeding and relapse status. Levels of 25(OH)D remained low in the exclusive breastfeeding group, yet rose significantly in the nonexclusive breastfeeding group regardless of season (P=.007, unadjusted; P=.02, adjusted for season). By 4 and 6 months after childbirth, 25(OH)D levels were, on average, 5 ng/mL lower in the women who breastfed exclusively compared with the nonbreastfeeding group (P=.001).Pregnancy and exclusive breastfeeding are strongly associated with low 25(OH)D levels in women with MS. However, these lower vitamin D levels were not associated with an increased risk of postpartum MS relapses. These data suggest that low vitamin D in isolation is not an important risk factor for postpartum MS relapses.

Abstract

The adaptive immune response in multiple sclerosis is complex. We have devised large scale arrays to measure the antibody response to myelin proteins and lipids. Despite the widespread immune responses to myelin, we have devised an inverse vaccine aimed at turning off key drivers of this diverse response. Clinical trials in patients with multiple sclerosis show that it is possible to constrain antibody responses to myelin on a large scale with this approach.

Abstract

The renin-angiotensin-aldosterone system (RAAS) is a key hormonal system regulating blood pressure. However, expression of RAAS components has recently been detected in immune cells, and the RAAS has been implicated in several mouse models of autoimmune disease. Here, we have identified Ang II as a paracrine mediator, sustaining inflammation in the CNS in the EAE mouse model of MS via TGF-beta. Ang II type 1 receptors (AT1Rs) were found to be primarily expressed in CNS-resident cells during EAE. In vitro, astrocytes and microglia responded to Ang II treatment by inducing TGF-beta expression via a pathway involving the TGF-beta-activating protease thrombospondin-1 (TSP-1). TGF-beta upregulation in astrocytes and microglia during EAE was blocked with candesartan (CA), an inhibitor of AT1R. Treatment of EAE with CA ameliorated paralysis and blunted lymphocyte infiltration into the CNS, outcomes that were also seen with genetic ablation of AT1Ra and treatment with an inhibitor of TSP-1. These data suggest that AT1R antagonists, frequently prescribed as antihypertensives, may be useful to interrupt this proinflammatory, CNS-specific pathway in individuals with MS.

Abstract

We present the first comparative analysis of serum immunoglobulin G reactivity profiles against the full spectrum of human myelin-associated proteins in multiple sclerosis patients and healthy control subjects. In both groups, serum antibodies display a consistent and prominent reaction to alphaB-crystallin (CRYAB) versus other myelin proteins. As an apparently major target for the adaptive immune system in humans, CRYAB selectively accumulates in oligodendrocytes, but not in astrocytes, or axons in so-called preactive multiple sclerosis lesions. These are clusters of activated HLA-DR-expressing microglia in myelinated normal-appearing white matter with no obvious leukocyte infiltration. They are found in most multiple sclerosis patients at all stages of disease. In these lesion areas, CRYAB in oligodendrocytes may come directly in contact with activated HLA-DR+ microglia. We demonstrate that CRYAB activates innate responses by microglia by stimulating the secretion of leukocyte-recruiting factors, including tumor necrosis factor, interleukin 17, CCL5, and CCL1, and immune-regulatory cytokines such as interleukin 10, transforming growth factor-beta, and interleukin 13. Together, these data suggest that CRYAB accumulation in preactive lesions may be part of a reversible reparative local response that involves both oligodendrocytes and microglia. At the same time, however, accumulated CRYAB may represent a major target for adaptive immune responses that could contribute to progression of preactive lesions to a stage of demyelination.

Abstract

Activation of the innate immune system by DNA containing hypomethylated CpG motifs has been implicated in the pathogenesis of systemic lupus erythematosus (SLE). Here, we examined the consequences of immunostimulatory CpG-oligodeoxynucleotide (ODN) and inhibitory GpG-ODN treatment in the NZB x NZW F1 (NZB/W) murine model of SLE. Beginning at 5 months of age, we administered CpG-ODN or GpG-ODN at regular intervals to female NZB/W animals. We also determined the effects of ODN administration on NZB/W mouse lymphocyte function, and the specificity of ODN binding to Toll-like receptors (TLRs) other than TLR-9. While CpG-ODN treatment did not appear to have a major impact on disease severity, GpG-ODN treatment significantly delayed the onset of proteinuria in NZB/W mice. Interestingly, short-term GpG-ODN treatment promoted Th2-type T and B cell responses, and inhibited B lymphocyte proliferation in vitro. On the other hand, extended GpG-ODN treatment did not result in sustained Th2 responses or significantly reduced renal disease. Moreover, the binding of CpG-ODN and GpG-ODN was not restricted to TLR-9 as both ODNs also interacted with TLR-3, TLR-7, and TLR-8. Taken together, the data indicate that the protective mechanism of GpG-ODN treatment in the NZB/W model of lupus nephritis involves modulating T cell cytokine profiles and B lymphocyte activation through the inhibition of several TLRs, including TLR-7 and TLR-9.

Abstract

To determine whether fluctuations in functional T-cell subsets can explain why multiple sclerosis (MS) relapses decline during pregnancy and increase in the postpartum period.Case-control study.Kaiser Permanente Northern California and Stanford University.Twenty-six pregnant women with MS and 24 age-matched, pregnant controls. Intervention We prospectively followed up the pregnant women with MS and the age-matched, pregnant controls; conducted structured interviews; and collected peripheral blood mononuclear cells during each trimester and 2, 4, 6, 9, and 12 months post partum.Sixteen functional cell types, including interferon-gamma (IFN-gamma)- and tumor necrosis factor-producing T-cell subsets, were measured using multicolor flow cytometry. Since these cell types may also fluctuate with pregnancy, lactational amenorrhea, or MS treatment, the data were analyzed taking into account these factors.Fifteen women with MS (58%) had relapses during the postpartum year. CD4(+)IFN-gamma-producing cells fluctuated with MS relapses, declining during pregnancy in women with MS (P < .001) and continuing to decline after parturition in women with relapses (P = .001), yet rising or remaining stable in women with nonrelapsing MS or healthy pregnant women. Lactational amenorrhea was associated with a rise in CD4(+)IFN-gamma-producing cells in women with MS (P = .009). In contrast, CD4(+) tumor necrosis factor-producing cells decreased during lactational amenorrhea in all groups of women and, once this was taken into account, obscured any relationship to MS relapses. CD8(+)IFN-gamma-producing cells were elevated in women with MS throughout the study (P < .001) but did not fluctuate with relapses.Our findings suggest that a decline in circulating CD4(+)IFN-gamma-producing cells leads to postpartum MS relapses. Our findings also suggest that the decline in these cells may begin during late pregnancy and that lactational amenorrhea induced by exclusive breastfeeding may be able to interrupt this process.

Abstract

Rheumatoid arthritis (RA) is an autoimmune synovitis characterized by the presence of anticitrullinated protein Abs, although the exact targets and role of anticitrullinated protein autoimmunity in the pathogenesis of RA remain to be defined. Fibrinogen, which can be citrullinated, has recently emerged as a candidate autoantigen. To determine whether autoimmunity against fibrinogen can mediate inflammatory arthritis, we immunized a variety of common mouse strains with fibrinogen and found that DBA/1 and SJL mice developed an inflammatory and erosive arthritis. Mice with fibrinogen-induced arthritis (FIA) possess fibrinogen-reactive T cells that produce the proinflammatory cytokines IL-6, IL-17, TNF-alpha, and IFN-gamma. FIA can be adoptively transferred with either plasma or fibrinogen-specific T cells from diseased mice. Mice with FIA possess rheumatoid factor, circulating immune complexes, and anticyclic citrullinated peptide Abs, all of which are characteristic of human RA. These observations demonstrate that fibrinogen is arthritogenic in mice and that the pathogenesis of FIA is mediated by both autoantibodies and fibrinogen-reactive T cells.

Abstract

The outcomes of clinical trials provide the most convincing data to clarify the role of particular cytokines in the pathogenesis of human diseases. The immunology community, for a variety of practical reasons, spends most of its research time and funds on studies in model systems, mainly mice. In this perspective I discuss results of clinical trials assessing the effect of blocking the differentiation and/or function of interleukin-17-producing CD4(+) T cells on human autoimmune disease, and devote more limited attention to corroborating preclinical studies from animal models. Thus far, these outcomes in human trials have been mixed, with notable success in psoriasis and Crohn's disease but a negative result in relapsing-remitting multiple sclerosis.

Abstract

Multiple sclerosis (MS) is a neurological disorder with a high burden on patient quality of life and medical rehabilitation services. Little is known about the acute hospitalization costs and characteristics. We examined the trends in MS hospitalizations from 1993 to 2006.The Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project was searched using the ICD-9 code 340 (MS). Diagnostic, treatment and administrative data were analyzed using basic statistical software.A total of 288,454 hospital admissions with the primary diagnosis of MS occurred between 1993 and 2006, an average of 20,604 admissions annually. The percentage admitted from the emergency department (ED) increased from 19.4 to 60.0% during 1993-2006. The mean cost for each inpatient increased from USD 7,965 to 20,076. The percentage of discharges to home health care increased from 8.6 to 14.9%, and the percentage of discharges to nursing homes and rehabilitation services increased from 8.3 to 22.6%. In 2006, Medicaid patients were significantly more likely to be admitted from the ED (p < 0.001). Medicare payers were significantly more likely to be discharged to a nursing home/rehabilitation (p < 0.0001).National health insurance policies have made measurable effects on MS disease management. MS is becoming more expensive to treat acutely, and improved treatment modalities geared toward decreasing acute flare-ups may provide substantial cost savings by reducing ED visits, inpatient hospitalizations and the need for rehabilitation.

Abstract

Statins are thought to have tumorolytic properties, reducing angiogenesis by inhibiting pro-angiogenic factors and inducing apoptosis of mural pericytes within the tumor vascular tree.An orthotopic mouse glioblastoma (GL-26) model was used to investigate the effect of simvastatin on glioblastoma vasculature in vivo. GL-26 cells were implanted into the striatum of C5LKa mice treated with either control, low- or high-dose simvastatin. Brains were analyzed for necrotic volume, apoptosis, morphology and pericytic cells within the vascular tree.Low-dose simvastatin increased necrosis and apoptosis compared to both control and high-dose simvastatin groups. High-dose simvastatin increased vessel caliber by reducing pericytic cells along the tumor vessel wall compared to both control and low-dose simvastatin groups.Simvastatin has a dual effect on tumorigenesis. At high doses, it may worsen instead of 'normalizing' tumor angio-architecture, albeit low doses affect tumor cell survival by promoting necrosis and apoptosis.

Abstract

Macrophages rapidly engulf apoptotic cells to limit the release of noxious cellular contents and to restrict autoimmune responses against self antigens. Although factors participating in recognition and engulfment of apoptotic cells have been identified, the transcriptional basis for the sensing and the silent disposal of apoptotic cells is unknown. Here we show that peroxisome proliferator-activated receptor-delta (PPAR-delta) is induced when macrophages engulf apoptotic cells and functions as a transcriptional sensor of dying cells. Genetic deletion of PPAR-delta decreases expression of opsonins such as complement component-1qb (C1qb), resulting in impairment of apoptotic cell clearance and reduction in anti-inflammatory cytokine production. This increases autoantibody production and predisposes global and macrophage-specific Ppard(-/-) mice to autoimmune kidney disease, a phenotype resembling the human disease systemic lupus erythematosus. Thus, PPAR-delta has a pivotal role in orchestrating the timely disposal of apoptotic cells by macrophages, ensuring that tolerance to self is maintained.

Abstract

It is widely debated whether MS is mediated solely by Th1, or solely by Th17, whether it might be mediated by both pathways, or perhaps by neither pathway. We must integrate the following four facts: first, MS lesions have a signature of IL-6-, IL-17-, osteopontin- and IFN-driven transcriptional activity. Second, MS is worsened with administration of IFN-gamma, the quintessential type 2 IFN and Th1 cytokine. Third, blockade of TNF-alpha worsened MS in clinical trials. Fourth, inhibiting the main driver of Th17, IL-23, failed to modulate relapsing-remitting MS (RRMS). Against this backdrop, standing outside the framework of the Th1 and Th17 pathways are the type 1 IFN, notably IFN-beta, the most widely used approved therapy for RRMS. A paper in this issue of the European Journal of Immunology demonstrates that IFN-beta suppresses production in CD4(+) T cells of both osteopontin and IL-17. In this commentary, the roles of these two molecules, i.e. osteopontin and IL-17, are discussed in relation to the pathogenesis of MS. Osteopontin may be more important than Th1 or Th17 in the pathogenesis of RRMS. Trials targeting this small integrin-binding protein ought to be pursued in RRMS.

Abstract

Induction of T helper 1 (Th1) to Th2 deviation through administration of self- or altered self-peptides holds promise for treatment of autoimmunity. However, administration of self-peptides in models of autoimmunity can result in anaphylactic reactions. Although both IgE and IgG1 antibodies might be involved in the development of anaphylaxis to myelin peptides in experimental autoimmune encephalomyelitis in mice, the effector cells and molecules involved are not fully understood. Here we show that systemic anaphylaxis to the self-antigen myelin oligodendrocyte glycoprotein (MOG) 35-55 can occur in mice lacking mast cells (Kit(W)/Kit(W-v) mice) or histamine (histidine decarboxylase-deficient mice), but is prevented in mice lacking IL-4. Treatment of mice with CV6209, a platelet-activating factor antagonist, slightly reduced the incidence of anaphylaxis to self-MOG35-55 in this model, but more effectively protected mice against anaphylaxis to this peptide when self-MOG35-55 was administered in a different immunization protocol that omitted the use of Bordetella pertussis toxin as an adjuvant at the time of immunization. Thus, anaphylactic reactions to self-MOG can occur in the absence of mast cells or histamine, key elements of the classical IgE-, mast cell-, and histamine-dependent pathway of anaphylaxis.

Abstract

Abnormal glycosylation is one of the hallmarks of the cancer cell and is associated with tumor invasion and metastasis. The development of tumor-associated carbohydrate antigen (TACA) vaccines has been problematic due to poor immunogenicity. However, when appropriate targets can be identified, passive immunization with monoclonal antibodies (mAbs) directed against TACAs has been shown to have antitumor activity. Fas ligand (FasL) is a transmembrane protein that induces apoptosis in cells expressing its receptor, Fas. When grafted into mice, FasL-expressing tumor cells break immunologic tolerance to self-antigens and induce antibody-mediated tumor immunity. Here, five IgM mAbs were produced from mice vaccinated with FasL-expressing B16F10 mouse melanoma cells. They recognize various syngeneic and allogeneic murine tumor cell lines. One mAb, TM10, recognizes a range of human tumor cell lines, including melanoma, prostate, and ovarian cancer. It does not bind to untransformed cells. The epitopes recognized by all the mAbs were carbohydrates expressed on proteins. Using carbohydrate microarrays, the antigenic targets of TM10 were found to be high-mannose core structures of N-linked glycans. In normal cells, high-mannose clusters are hidden by extensive saccharide branching but they become exposed in cancer cells as a result of abnormal glycosylation pathways. Vaccination with FasL-expressing tumors therefore enables the immune system to break tolerance to self-antigens, allowing identification of novel TACAs that can form the basis of future humoral anticancer therapy.

New targets for treatment of multiple sclerosis13th Symposium of the European-Charcot-FoundationSteinman, L.ELSEVIER SCIENCE BV.2008: 1–4

Abstract

By studying gene transcripts in active lesions of multiple sclerosis via robotic sequencing and gene chips, as well as studying the very same tissue via proteomics, we have discovered several targets at the tipping points in pathophysiologic pathways controlling relapse and remission in multiple sclerosis. In this Charcot Lecture, I shall focus on osteopontin-the binding partner for alpha4 beta 1 integrin, on alpha B crystallin and on two members of the coagulation cascade tissue factor and the inhibitor of protein C. These four proteins are critical in controlling relapse and remission in MS.

Abstract

The IL-23/IL-17 pathway plays an important role in chronic inflammatory diseases, including inflammatory bowel disease. In inflammatory bowel disease, intestinal epithelial cells are an important source of chemokines that recruit inflammatory cells. We examined the effect of IL-17 on chemokine expression of HT-29 colonic epithelial cells. IL-17 strongly repressed TNF-alpha-stimulated expression of CXCL10, CXCL11, and CCL5, but synergized with TNF-alpha for induction of CXCL8, CXCL1, and CCL20 mRNAs. For CXCL10, IL-17 strongly inhibited promoter activity but had no effect on mRNA stability. In contrast, for CXCL8, IL-17 slightly decreased promoter activity but stabilized its normally unstable mRNA, leading to a net increase in steady-state mRNA abundance. IL-17 synergized with TNF-alpha in transactivating the epidermal growth factor receptor (EGFR) and in activating ERK and p38 MAPK. The p38 and ERK pathway inhibitors SB203580 and U0126 reversed the repressive effect of IL-17 on CXCL10 mRNA abundance and promoter activity and also reversed the inductive effect of IL-17 on CXCL8 mRNA, indicating that MAPK signaling mediates both the transcriptional repression of CXCL10 and the stabilization of CXCL8 mRNA by IL-17. The EGFR kinase inhibitor AG1478 partially reversed the effects of IL-17 on CXCL8 and CXCL10 mRNA, demonstrating a role for EGFR in downstream IL-17 signaling. The overall results indicate a positive effect of IL-17 on chemokines that recruit neutrophils (CXCL8 and CXCL1), and Th17 cells (CCL20). In contrast, IL-17 represses expression of CXCL10, CXCL11, and CCR5, three chemokines that selectively recruit Th1 but not other effector T cells.

Abstract

gammadelta T cells uniquely contribute to host immune defense, but how this is accomplished remains unclear. Here, we analyzed the nonclassical major histocompatibility complex class I T10 and T22-specific gammadelta T cells in mice and found that encountering antigen in the thymus was neither required nor inhibitory for their development. But when triggered through the T cell receptor, ligand-naive lymphoid-gammadelta T cells produced IL-17, whereas ligand-experienced cells made IFN-gamma. Immediately after immunization, a large fraction of IL-17(+) gammadelta T cells were found in the draining lymph nodes days before the appearance of antigen-specific IL-17(+) *beta T cells. Thus, thymic selection determines the effector fate of gammadelta T cells rather than constrains their antigen specificities. The swift IL-17 response mounted by antigen-naive gammadelta T cells suggests a critical role for these cells at the onset of an acute inflammatory response to novel antigens.

Abstract

Inhibitors of the 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase enzyme (statins) are cholesterol-lowering drugs that have shown promise as therapeutic agents in various animal models of autoimmune disease. The results of initial clinical trials with statins in multiple sclerosis and rheumatoid arthritis have also been encouraging. In this study, we attempted to treat a widely studied murine model of spontaneous systemic lupus erythematosus (SLE) with atorvastatin.(NZB x NZW)F1 (NZB/NZW) mice received daily oral doses of atorvastatin for 20 weeks. The mice were monitored weekly for survival and proteinuria. Anti-double-stranded DNA (anti-dsDNA) antibody levels in sera were determined by enzyme-linked immunosorbent assay (ELISA). T lymphocyte cytokine production in vitro, as well as cytokine levels in vivo, were measured by ELISA. T cell proliferation was assessed by thymidine incorporation assay. Serum cholesterol levels were determined using a standard fluorometric assay. Kidney tissue was harvested and evaluated for pathologic changes.In NZB/NZW mice, oral atorvastatin had significant effects on T cell proliferation and cytokine production in vitro. Atorvastatin also induced significant increases in serum levels of interleukin-4. However, atorvastatin treatment in NZB/NZW mice had no significant impact on proteinuria, survival, serum anti-dsDNA antibody and cholesterol levels, or extent of renal disease.Monotherapy with oral atorvastatin has no protective effects in a murine model of spontaneous SLE. The efficacy of atorvastatin in human SLE remains to be determined.

Abstract

Although interferon-beta is the most popular treatment for multiple sclerosis, its mechanism of action remains enigmatic. In this issue of Immunity, Prinz et al. (2008) elucidate an intriguing portrait of the pleiotropic effects of type 1 interferons in taming brain inflammation.

Abstract

Transplanted bone marrow-derived cells (BMDCs) have been reported to fuse with cells of diverse tissues, but the extremely low frequency of fusion has led to the view that such events are biologically insignificant. Nonetheless, in mice with a lethal recessive liver disease (tyrosinaemia), transplantation of wild-type BMDCs restored liver function by cell fusion and prevented death, indicating that cell fusion can have beneficial effects. Here we report that chronic inflammation resulting from severe dermatitis or autoimmune encephalitis leads to robust fusion of BMDCs with Purkinje neurons and formation of hundreds of binucleate heterokaryons per cerebellum, a 10-100-fold higher frequency than previously reported. Single haematopoietic stem-cell transplants showed that the fusogenic cell is from the haematopoietic lineage and parabiosis experiments revealed that fusion can occur without irradiation. Transplantation of rat bone marrow into mice led to activation of dormant rat Purkinje neuron-specific genes in BMDC nuclei after fusion with mouse Purkinje neurons, consistent with nuclear reprogramming. The precise neurological role of these heterokaryons awaits elucidation, but their frequency in brain after inflammation is clearly much higher than previously appreciated.

Abstract

A role for CD4(+)CD25(+) regulatory T cells (Tregs) in the control of allergic diseases has been postulated. We developed a mouse model in which anaphylaxis is induced in SJL mice by immunization and challenge with the fragment of self myelin proteolipid protein (PLP)(139-151), that is not expressed in the thymus, but not with fragment 178-191 of the same protein, that is expressed in the thymus. In this study, we show that resistance to anaphylaxis is associated with naturally occurring CD4(+)CD25(+) Tregs specific for the self peptide expressed in the thymus. These cells increase Foxp3 expression upon Ag stimulation and suppress peptide-induced proliferation of CD4(+)CD25(-) effector T cells. Depletion of Tregs with anti-CD25 in vivo significantly diminished resistance to anaphylaxis to PLP(178-191), suggesting an important role for CD4(+)CD25(+) Tregs in preventing the development of allergic responses to this thymus-expressed peptide. These data indicate that naturally occurring CD4(+)CD25(+) Tregs specific for a peptide expressed under physiological conditions in the thymus are able to suppress the development of a systemic allergic reaction to self.

Abstract

Experimental autoimmune encephalomyelitis is a widely used animal model to understand not only multiple sclerosis but also basic principles of immunity. The disease is scored typically by observing signs of paralysis, which do not always correspond with pathological changes.Experimental autoimmune encephalomyelitis was induced in transgenic mice expressing an injury responsive luciferase reporter in astrocytes (GFAP-luc). Bioluminescence in the brain and spinal cord was measured non-invasively in living mice. Mice were sacrificed at different time points to evaluate clinical and pathological changes. The correlation between bioluminescence and clinical and pathological EAE was statistically analyzed by Pearson correlation analysis.Bioluminescence from the brain and spinal cord correlates strongly with severity of clinical disease and a number of pathological changes in the brain in EAE. Bioluminescence at early time points also predicts severity of disease.These results highlight the potential use of bioluminescence imaging to monitor neuroinflammation for rapid drug screening and immunological studies in EAE and suggest that similar approaches could be applied to other animal models of autoimmune and inflammatory disorders.

Abstract

Anti-citrullinated protein antibodies have a diagnostic role in rheumatoid arthritis (RA); however, little is known about their origins and contribution to pathogenesis. Citrullination is the post-translational conversion of arginine to citrulline by peptidyl arginine deiminase, and increased citrullination of proteins is observed in the joint tissue in RA and in brain tissue in multiple sclerosis (MS).We applied synovial and myelin protein arrays to examine epitope spreading of B cell responses to citrullinated epitopes in both the collagen-induced arthritis (CIA) model for RA and the experimental autoimmune encephalomyelitis (EAE) model for MS. Synovial and myelin protein arrays contain a spectrum of proteins and peptides, including native and citrullinated forms, representing candidate autoantigens in RA and MS, respectively. We applied these arrays to characterise the specificity of autoantibodies in serial serum samples derived from mice with acute and chronic stages of CIA and EAE.In samples from pre-disease CIA and acute-disease EAE, we observed autoantibody targeting of the immunising antigen and responses to a limited set of citrullinated epitopes. Over the course of diseases, the autoantibody responses expanded to target multiple citrullinated epitopes in both CIA and EAE. Using immunoblotting and mass spectrometry analysis, we identified citrullination of multiple polypeptides in CIA joint and EAE brain tissue that have not previously been described as citrullinated.Our results suggest that anti-citrulline antibody responses develop in the early stages of CIA and EAE, and that autoimmune inflammation results in citrullination of joint proteins in CIA and brain proteins in EAE, thereby creating neoantigens that become additional targets in epitope spreading of autoimmune responses.

Abstract

We investigated whether atorvastatin (AT) was capable of protecting animals from acute graft-versus-host disease (aGVHD) across major histocompatibility complex (MHC) mismatch barriers. AT treatment of the donor induced a Th-2 cytokine profile in the adoptively transferred T cells and reduced their in vivo expansion, which translated into significantly reduced aGVHD lethality. Host treatment down-regulated costimulatory molecules and MHC class II expression on recipient antigen-presenting cells (APCs) and enhanced the protective statin effect, without impacting graft-versus-leukemia (GVL) activity. The AT effect was partially reversed in STAT6(-/-) donors and abrogated by L-mevalonate, indicating the relevance of STAT6 signaling and the L-mevalonate pathway for AT-mediated aGVHD protection. AT reduced prenylation levels of GTPases, abolished T-bet expression, and increased c-MAF and GATA-3 protein in vivo. Thus, AT has significant protective impact on aGVHD lethality by Th-2 polarization and inhibition of an uncontrolled Th-1 response while maintaining GVL activity, which is of great clinical relevance given the modest toxicity profile of AT.

Abstract

Autoimmune encephalomyelitis, a mouse model for multiple sclerosis, is characterized by the activation of immune cells, demyelination of axons in the CNS, and paralysis. We found that TGF-beta1 synthesis in glial cells and TGF-beta-induced signaling in the CNS were activated several days before the onset of paralysis in mice with autoimmune encephalomyelitis. While early production of TGF-beta1 was observed in glial cells TGF-beta signaling was activated in neurons and later in infiltrating T cells in inflammatory lesions. Systemic treatment with a pharmacological inhibitor of TGF-beta signaling ameliorated the paralytic disease and reduced the accumulation of pathogenic T cells and expression of IL-6 in the CNS. Priming of peripheral T cells was not altered, nor was the generation of TH17 cells, indicating that this effect was directed within the brain, yet affected the immune system. These results suggest that early production of TGF-beta1 in the CNS creates a permissive and dangerous environment for the initiation of autoimmune inflammation, providing a rare example of the brain modulating the immune system. Importantly, inhibition of TGF-beta signaling may have benefits in the treatment of the acute phase of autoimmune CNS inflammation.

Abstract

Recent evidence points to tryptophan (Trp) degradation as a potent immunosuppressive mechanism involved in the maintenance of immunological tolerance. Both Trp depletion and downstream Trp catabolites (TCs) appear to synergistically confer protection against excessive inflammation. In this review, we give an overview of the immunosuppressive properties of Trp degradation with special focus on TCs. Constitutive and inducible Trp degradation in different cell types and tissues of human and murine origin is summarized. We address the influence of Trp degradation on different aspects of autoimmune disorders such as multiple sclerosis. Possible therapeutic approaches for autoimmune disorders targeting Trp degradation are presented, and key issues relevant for the development of such therapeutic strategies are discussed.

Abstract

Statins are a class of drugs that inhibit 3-hydroxy-3-methylglutaryl-coenzyme A (HMGcoA) reductase, a critical enzyme in the mevalonate pathway. Several reports document that statins may prevent different human cancers. However, whether or not statins can prevent cancer is controversial due to discordant results. One possible explanation for these conflicting conclusions is that only some tumors or specific statins may be effective. Here, we demonstrate in an in vivo transgenic model in which atorvastatin reverses and prevents the onset of MYC-induced lymphomagenesis, but fails to reverse or prevent tumorigenesis in the presence of constitutively activated K-Ras (G12D). Using phosphoprotein fluorescence-activated cell sorter (FACS) analysis, atorvastatin treatment was found to result in the inactivation of the Ras and ERK1/2 signaling pathways associated with the dephosphorylation and inactivation of MYC. Correspondingly, tumors with a constitutively activated K-Ras (G12D) did not exhibit dephosphorylation of ERK1/2 and MYC. Atorvastatin's effects on MYC were specific to the inhibition of HMGcoA reductase, as treatment with mevalonate, the product of HMG-CoA reductase activity, abrogated these effects and inhibited the ability of atorvastatin to reverse or suppress tumorigenesis. Also, RNAi directed at HMGcoA reductase was sufficient to abrogate the neoplastic properties of MYC-induced tumors. Thus, atorvastatin, by inhibiting HMGcoA reductase, induces changes in phosphoprotein signaling that in turn prevent MYC-induced lymphomagenesis.

Abstract

The adaptive immune response in multiple sclerosis (MS) targets various myelin proteins and even some inducible heat shock proteins. A few attempts have been made to tolerize relapsing-remitting patients with MS to either full-length myelin basic protein or to a key peptide epitope between residues 83-99. These trials have demonstrated that this approach may potentially provide benefit to patients with relapsing- remitting MS. However, manipulation of responses to myelin proteins can have deleterious effects. The immune response to myelin components is positioned at a key tipping point in the pathophysiology of the disease. Clarification of the key target antigens in MS, and better understanding of practical methods to attain tolerance to a wide variety of myelin and neuronal molecules will provide the basis for the ultimately successful antigen specific therapy.

Abstract

Statins, inhibitors of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase, are well-established agents to lower cholesterol levels and prevent cardiovascular morbidity. Independent of their lipid-lowering properties, statins have been shown to exert pleiotropic immunomodulatory effects in various animal models of human autoimmune disease. In experimental autoimmune encephalomyelitis, a murine model for multiple sclerosis, statins prevented disease onset and even reversed paralysis when treatment was initiated after experimental autoimmune encephalomyelitis was fully established. Furthermore, well-tolerated oral statins were recently shown to exert synergistic benefit in experimental autoimmune encephalomyelitis in combination with existing agents for multiple sclerosis therapy. Based primarily on these encouraging results, statins are now being tested in clinical trials as a monotherapy for multiple sclerosis, as well as in combination with approved disease-modifying therapies.

Abstract

The role of autoantibodies in the pathogenesis of multiple sclerosis (MS) and other demyelinating diseases is controversial, in part because widely used western blotting and ELISA methods either do not permit the detection of conformation-sensitive antibodies or do not distinguish them from conformation-independent antibodies. We developed a sensitive assay based on self-assembling radiolabeled tetramers that allows discrimination of antibodies against folded or denatured myelin oligodendrocyte glycoprotein (MOG) by selective unfolding of the antigen domain. The tetramer radioimmunoassay (RIA) was more sensitive for MOG autoantibody detection than other methodologies, including monomer-based RIA, ELISA or fluorescent-activated cell sorting (FACS). Autoantibodies from individuals with acute disseminated encephalomyelitis (ADEM) selectively bound the folded MOG tetramer, whereas sera from mice with experimental autoimmune encephalomyelitis induced with MOG peptide immunoprecipitated only the unfolded tetramer. MOG-specific autoantibodies were identified in a subset of ADEM but only rarely in adult-onset MS cases, indicating that MOG is a more prominent target antigen in ADEM than MS.

Abstract

Heme oxygenase-1 (HO-1, encoded by HMOX1) dampens inflammatory reactions via the catabolism of heme into CO, Fe, and biliverdin. We report that expression of HO-1 dictates the pathologic outcome of experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis (MS). Induction of EAE in Hmox1(-/- )C57BL/6 mice led to enhanced CNS demyelination, paralysis, and mortality, as compared with Hmox1(+/+) mice. Induction of HO-1 by cobalt protoporphyrin IX (CoPPIX) administration after EAE onset reversed paralysis in C57BL/6 and SJL/J mice and disease relapse in SJL/J mice. These effects were not observed using zinc protoporphyrin IX, which does not induce HO-1. CoPPIX protection was abrogated in Hmox1(-/-) C57BL/6 mice, indicating that CoPPIX acts via HO-1 to suppress EAE progression. The protective effect of HO-1 was associated with inhibition of MHC class II expression by APCs and inhibition of Th and CD8 T cell accumulation, proliferation, and effector function within the CNS. Exogenous CO mimicked these effects, suggesting that CO contributes to the protective action of HO-1. In conclusion, HO-1 or exposure to its end product CO counters autoimmune neuroinflammation and thus might be used therapeutically to treat MS.

Abstract

Current therapies for rheumatoid arthritis (RA) and other autoimmune diseases non-specifically suppress immune function, and there is great need for fundamental approaches such as antigen-specific tolerizing therapy. In this paper we describe development of antigen-specific tolerizing DNA vaccines to treat collagen-induced arthritis (CIA) in mice, and use of protein microarrays to monitor response to therapy and to identify potential additional autoimmune targets for next generation vaccines. We demonstrate that tolerizing DNA vaccines encoding type II collagen (CII) reduced the incidence and severity of CIA. Atorvastatin, a statin drug found to reduce the severity of autoimmunity, potentiated the effect of DNA vaccines encoding CII. Analysis of cytokines produced by collagen-reactive T cells derived from mice receiving tolerizing DNA encoding CII, as compared to control vaccines, revealed reduced production of the pro-inflammatory cytokines IFN-gamma and TNF-alpha. Arthritis microarray analysis demonstrated reduced spreading of autoantibody responses in mice treated with DNA encoding CII. The development of tolerizing DNA vaccines, and the use of antibody profiling to guide design of and to monitor therapeutic responses to such vaccines, represents a promising approach for the treatment of RA and other autoimmune diseases.

Abstract

Tyrosine kinases play a central role in the activation of signal transduction pathways and cellular responses that mediate the pathogenesis of rheumatoid arthritis. Imatinib mesylate (imatinib) is a tyrosine kinase inhibitor developed to treat Bcr/Abl-expressing leukemias and subsequently found to treat c-Kit-expressing gastrointestinal stromal tumors. We demonstrate that imatinib potently prevents and treats murine collagen-induced arthritis (CIA). We further show that micromolar concentrations of imatinib abrogate multiple signal transduction pathways implicated in RA pathogenesis, including mast cell c-Kit signaling and TNF-alpha release, macrophage c-Fms activation and cytokine production, and fibroblast PDGFR signaling and proliferation. In our studies, imatinib attenuated PDGFR signaling in fibroblast-like synoviocytes (FLSs) and TNF-alpha production in synovial fluid mononuclear cells (SFMCs) derived from human RA patients. Imatinib-mediated inhibition of a spectrum of signal transduction pathways and the downstream pathogenic cellular responses may provide a powerful approach to treat RA and other inflammatory diseases.

Abstract

Statins, inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase, are widely prescribed for their cholesterol-lowering properties to reduce atherogenesis and cardiovascular morbidity. Over recent years, statins have also been shown to exert pleiotropic immunomodulatory effects that might be of therapeutic benefit in autoimmune disorders. The primary mechanism by which statins alter immune function appears to be mediated through the inhibition of post-translational protein prenylation of small GTP-binding proteins and is largely independent of lipid-lowering. In experimental autoimmune encephalomyelitis (EAE), the mouse model for multiple sclerosis (MS), statins prevent or reverse paralysis and were recently shown to exert synergistic benefit when combined with agents approved for MS therapy. Based primarily upon the beneficial effects in EAE, statins are now being tested in patients in MS clinical trials.

State of the art. Four easy pieces: interconnections between tissue injury, intermediary metabolism, autoimmunity, and chronic degeneration.Proceedings of the American Thoracic SocietySteinman, L.2006; 3 (6): 484-486

Abstract

Four questions are posed: (1) Can tissue damage itself provoke autoimmunity? (2) Can genetic mutations of key structures produce tissue pathology and thus provoke autoimmunity? (3) Can acute immune damage produce tissue degeneration without further hallmarks of an immune response? (4) Can intermediary metabolism modulate immune damage to tissues? Four answers are given: (1) Tissue injury itself may lead to autoimmunity. Both innate and adaptive immunity may arise as a response to tissue injury, and the immune attack can further damage tissue. (2) Genetic mutations can lead to an immune response indistinguishable from autoimmunity, exemplified from Duchenne's Muscular Dystrophy and X-linked adrenoleukodystrophy. (3) Chronic immune damage may lead to tissue degeneration, with or without further hallmarks of an immune response. Variations on this theme, including inverse scenarios, are also possible: Inborn errors of metabolism may lead to tissue damage that may provoke an adaptive and or innate immune response. The immune response might further damage tissue. (4) Finally, perturbations of intermediary metabolism may modulate the immune response, controlling the extent of immune-mediated damage. Examples are taken from perturbations in the cholesterol pathway that influence the characteristics of the immune response, and with tryptophan metabolites that modulate autoimmunity and graft rejection. Inflammatory, degenerative, and autoimmune neurological disease will be discussed in terms of their implications for pathogenic mechanisms underlying chronic obstructive pulmonary disease.

Abstract

In their Point of View entitled "Experimental Allergic Encephalomyelitis: A Misleading Model of Multiple Sclerosis," Sriram and Steiner(1) wrote, "The most disappointing aspect of EAE [experimental allergic encephalomyelitis] as a potential model for MS is its almost total inability to point toward a meaningful therapy or therapeutic approach for MS." Actually, EAE has led directly to the development of three therapies approved for use in multiple sclerosis (MS): glatiramer acetate, mitoxantrone, and natalizumab. Several new approaches to MS are in clinical trials based on positive indications in preclinical work relying on EAE. New clues to the pathogenesis of MS and new potential surrogate markers for MS are shown from research involving EAE when it is critically coupled with actual findings in MS. There are pitfalls in overreliance on the EAE model, or on any animal model for any human disease. Nevertheless, over the past 73 years, the EAE model has proved itself remarkably useful for aiding research on MS.

Abstract

In recent years, knowledge about the physiological functions of the Nogo-A protein has grown considerably, and this molecule has evolved from being one of the most important axonal regrowth inhibitors present in central nervous system (CNS) myelin, to several other potentially important roles in different areas such as nervous system development, epilepsy, vascular physiology, muscle pathology and CNS tumors. Therapeutically, targeting the Nogo-A protein by means of the immune response has been tried in an attempt to block neurite growth inhibition and promote regeneration in spinal cord injury models; the immune response to Nogo-A, however, has not been extensively studied. We propose to review recent evidence that Nogo-A may also play an important role in autoimmune demyelinating diseases such as experimental autoimmune encephalomyelitis and multiple sclerosis, including that Nogo-66 derived epitopes are encephalitogenic antigens in susceptible mouse strains, and that the immune response to Nogo-66 antigens includes both strong T cell and B cell activation, with epitope spreading of the antibody response to other myelin molecules. In CNS immunotherapy, careful targeting of neural self-antigens is a prerequisite in order to avoid unexpected deleterious effects, and increasing knowledge about the immune response to Nogo-A may provide a safe basis for the development of relevant therapeutic alternatives for several neurological conditions.

Abstract

The aim of this review is to describe the recent findings regarding the pathogenesis of multiple sclerosis and their translation to new therapies.Basic research is providing new insights into the immune elements involved in the pathogenesis of multiple sclerosis, both in the periphery as well as in the central nervous system. Unveiling the complex interplay of the molecules involved in the immunological cascade of the disease supplies new targets for the development of new immunotherapeutic strategies. Similarly, clinical studies and identification of distinct subgroups of patients based on their responsiveness to immunotherapies provides support for the existence of immunopathological disease subtypes that seem to require different therapeutic approaches. These studies extend the theoretical basis that facilitates development of neuroprotective and repair-promoting therapeutic strategies.The application of novel and cutting-edge technologies in the fields of genomics and proteomics is providing a better understanding of the genetic and environmental factors involved in multiple sclerosis susceptibility and progression, as well as the detection of biomarkers for disease activity and response to therapy. Implementation of these facilitates identification of new targets for therapy towards tailoring treatment to the individual patient with multiple sclerosis.

Abstract

Three patients have developed progressive multifocal leukoencephalopathy while being treated with natalizumab for their autoimmune diseases. One patient had relapsing-remitting multiple sclerosis (RRMS), one had Crohn's disease, and one (who had been enrolled in an RRMS phase III trial) had no evidence of multiple sclerosis on autopsy. The patient with RRMS now has severe, permanent neurologic damage and the other two patients died. In this article, we recommend revised entry and diagnostic criteria to prevent enrollment of RRMS patients with a favorable prognosis or questionable diagnosis into trials of drugs with unknown safety profiles. In light of the risk of progressive multifocal leukoencephalopathy, we strongly recommend that RRMS patients who are at low risk of disability not be treated with natalizumab. Finally, we discuss what additional natalizumab efficacy data need to be presented before any decisions should be made about treating RRMS patients with a high risk of developing long-term disability.

Abstract

Statins have been prescribed extensively for their cholesterol-lowering properties and efficacy in cardiovascular disease. However, compelling evidence now exists that statins also have extensive immunomodulatory properties that operate independently of lipid lowering. Consequently, much attention has been directed towards their potential as therapeutic agents for the treatment of autoimmune disease. Modulation of post-translational protein prenylation seems to be a key mechanism by which statins alter immune function. In this Review, the effect of statin therapy on immune function, and how this relates to the pathogenesis of autoimmune disease, is reviewed alongside current opinion of what the key biological targets of statins are.

Abstract

Disturbances in crosstalk between the immune system and the sympathetic nervous system (SNS) can contribute to the pathogenesis of Th1-mediated autoimmunity. Recent studies indicate that neuropeptide Y (NPY) has a major role in the regulation of Th1 responses. The precise role of NPY has been an enigma, but a recent study provides a breakthrough, demonstrating that NPY has a bimodal role as a negative regulator of T cells and an activator of antigen-presenting cell function.

Abstract

One approach to improving efficacy in MS therapy is to identify medications that provide additive or synergistic benefit in combination. Orally administered cholesterol-lowering HMG-CoA reductase inhibitors (known as statins), which exhibit immunomodulatory properties and are effective in treatment of the MS model EAE, are being tested in MS. As atorvastatin can enhance protective Th2 responses and has a different mechanism of action than glatiramer acetate (GA), a parenterally administered immunomodulatory agent approved for MS treatment, we tested whether the combination of these agents could be beneficial in EAE. Combination therapy using suboptimal doses of atorvastatin and GA prevented or reversed clinical and histologic EAE. Secretion of proinflammatory Th1 cytokines was reduced--and conversely Th2 cytokine secretion was increased--in these mice, but not in mice treated with each drug alone at the same doses. Monocytes treated with the combination of suboptimal doses of atorvastatin and GA secreted an antiinflammatory type II cytokine pattern and, when used as APCs, promoted Th2 differentiation of naive myelin-specific T cells. Our results demonstrate that agents with different mechanisms of immune modulation can combine in a synergistic manner for the treatment of CNS autoimmunity and provide rationale for testing the combination of atorvastatin and GA in MS.

Abstract

Histamine can modulate the cytokine network and influence Th1 and Th2 balance and Ab-isotype switching. Thus, pharmacological blockade or genetic deletion of specific histamine receptors has been shown to reduce the severity of experimental autoimmune encephalomyelitis (EAE), a prototypic Th1-mediated disease with similarities to human multiple sclerosis. To study the comprehensive contribution of endogenous histamine to the expression of EAE, we attempted to induce EAE in histidine decarboxylase-deficient mice, which are genetically unable to make histamine. In this study, we show that EAE is significantly more severe in HDC-/-, histamine-deficient mice, with diffuse inflammatory infiltrates, including a prevalent granulocytic component, in the brain and cerebellum. Unlike splenocytes from wild-type mice, splenocytes from HDC-/- mice do not produce histamine in response to the myelin Ag, whereas production of IFN-gamma, TNF, and leptin are increased in HDC-/- splenocytes in comparison to those from wild-type mice. Endogenous histamine thus appears to regulate importantly the autoimmune response against myelin and the expression of EAE, in this model, and to limit immune damage to the CNS. Understanding which receptor(s) for histamine is/are involved in regulating autoimmunity against the CNS might help in the development of new strategies of treatment for EAE and multiple sclerosis.

Abstract

Statins, a family of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, are used primarily to reduce atherogenesis and cardiovascular morbidity. Surprisingly, they have also been shown to have immunomodulatory properties that might be of benefit for the treatment of autoimmune disorders. Statins can prevent and even reverse ongoing paralysis in experimental autoimmune encephalomyelitis--the mouse model for multiple sclerosis--and on the basis of these findings, statins are now being tested in patients with multiple sclerosis in clinical trials.

Virtues and pitfalls of EAE for the development of therapies for multiple sclerosisTRENDS IN IMMUNOLOGYSteinman, L., Zamvil, S. S.2005; 26 (11): 565-571

Abstract

Experimental autoimmune encephalomyelitis (EAE) is a useful model for aiding the development of new treatments for MS. All therapies approved for MS ameliorate EAE. Two approved medications, glatiramer acetate and Natalizumab, were developed directly from studies in EAE. Several trials are ongoing in MS after success in EAE, including altered peptide ligands of myelin, DNA vaccines and statins. However, EAE has failed to predict the outcome of certain approaches. The reasons underlying such failures are discussed here.

Abstract

In the management of patients with multiple sclerosis (MS), providers are all faced with the highly formidable challenge of ascertaining whether, and to what degree, disease-modifying therapy is effective in the individual patient. While much has been learned in randomized, controlled clinical trials, we cannot simply extrapolate the outcomes of these initiatives and apply them to the care of a single patient. In the future, the application of pharmacogenetic techniques, proteomics, and microarray analysis will yield novel profiling information on individual patients that will substantially refine the specific therapeutic questions of relevance: (1) What is the best treatment for an individual patient? (2) Which patients require intensive therapeutic combination regimens to optimize control of the disease process? (3) What are the appropriate drug dosing targets for an individual patient? and (4) Which patients will be predisposed to the development of drug-related adverse events? Such data may provide a novel variable of drug responsiveness that will mandate its inclusion into the process of covariate analyses for clinical trials.

Abstract

Multiple sclerosis (MS) is a complex immune-mediated disease resulting largely from an autoimmune attack against components of central nervous system myelin, including several proteins and lipids. Knowledge about the details of this anomalous immune response has come mostly from studies in the animal model experimental autoimmune encephalomyelitis (EAE). In this model, it has been possible to prevent and effectively treat established disease through several antigen-specific therapeutic strategies, which have included administration of whole myelin or myelin proteins by various routes, random copolymers consisting of the main major histocompatability complex (MHC) and T-cell receptor (TCR) contact amino acid residues, altered peptide ligands of dominant myelin epitopes in which one or more residues are selectively substituted, and lately DNA vaccination encoding self-myelin antigens. However, there have been difficulties in making successful transitions from animal models to human clinical trials, due either to lack of efficacy or unforeseen complications. Despite these problems, antigen-specific therapies have retained their attraction for clinicians and scientists alike, and hopefully the upcoming generation of agents--including altered peptide ligands and DNA vaccines--will benefit from the increasing knowledge about this disease and surmount existing difficulties to make an impact in the treatment of multiple sclerosis.

Abstract

Major advancements have been achieved in our ability to diagnose multiple sclerosis (MS) and to commence treatment intervention with agents that can favorably affect the disease course. Although MS exacerbations and the emergence of disability constitute the more conspicuous aspects of the disease process, evidence has confirmed that most of the disease occurs on a constitutive and occult basis. Disease-modifying therapies appear to be modest in the magnitude of their treatment effects, particularly in the progressive stage of the disease. Therapeutic strategies currently used for MS primarily target the inflammatory cascade. Several potential mechanisms appear to be involved in the progression of MS. Characterizing these mechanisms will result in a better understanding of the various forms of the disorder and how to effectively treat its clinical manifestations. It is our objective within this 2-part series on progression in MS to offer both evidence-based observations and hypothesis-driven expert perspectives on what constitutes the cause of progression in MS. We have chosen areas of inquiry that appear to have been most productive in helping us to better conceptualize the landscape of what MS looks like pathologically, immunologically, neuroscientifically, radiographically, and genetically. We have attempted to advance hypotheses focused on a deeper understanding of what contributes to the progression of this illness and to illustrate new technical capabilities that are catalyzing novel research initiatives targeted at achieving a more complete understanding of progression in MS.

Abstract

Molecular mimics of self-antigens can behave as altered peptide ligands and serve to ameliorate autoimmune disease. Analysis of experimental autoimmune encephalomyelitis with proteomic autoantibody microarrays reveals that there might exist a wide variety of microbes with features that mimic self-epitopes. Autoimmunity could therefore be modulated via microbial immunity, which may account for relapse and remission of ongoing disease.

Abstract

Nogo-66, the extracellular 66 aa loop of the Nogo-A protein found in CNS myelin, interacts with the Nogo receptor and has been proposed to mediate inhibition of axonal regrowth. It has been shown that immunization with Nogo-A promotes recovery in animal models of spinal cord injury through induction of Ab production. In this report, studies were performed to characterize the immune response to Nogo-66 and to determine the role of Nogo in experimental autoimmune encephalomyelitis (EAE). Immunization of EAE-susceptible mouse strains with peptides derived from Nogo-66 induced a CNS immune response with clinical and pathological similarities to EAE. The Nogo-66 peptides elicited strong T cell responses that were not cross-reactive to other encephalitogenic myelin Ags. Using a large scale spotted microarray containing proteins and peptides derived from a wide spectrum of myelin components, we demonstrated that Nogo-66 peptides also generated a specific Ab response that spreads to several other encephalitogenic myelin Ags following immunization. Nogo-66-specific T cell lines ameliorated established EAE, via Nogo-66-specific Th2 cells that entered the CNS. These results indicate that some T cell and B cell immune responses to Nogo-66 are associated with suppression of ongoing EAE, whereas other Nogo-66 epitopes can be encephalitogenic.

The multifaceted role of transglutaminase in neurodegeneration: Review article8th International Congress on Amino Acids and ProteinsKarpuj, M., Steinman, L.SPRINGER.2004: 373–79

Abstract

A critical role for transglutaminase [TGase] has been hypothesized in the pathogenesis of the CAG trinucleotide repeat diseases, characterized by proteins with abnormal expansions of a polyglutamine domain. In the last few years the involvement of TGase in neurodegenerative diseases [NDS], including its role in aggregate formation, has been broadened to include Alzheimer's [AD] and Parkinson's Disease [PD]. It is clear that reduction of TGase activity is beneficial for prolonged survival in mouse models of NDS. The pathological progression of these diseases might reflect in part increases of TGase induced aggregates, or changes in other pathways influenced by increases in TGase activity. Neurodegeneration may be influenced by increased TGase activity affecting apoptosis, modulation of GTPase activity and signal transduction. This review will focus on the leading hypotheses in relation to both old and new experimental results.

Abstract

Numerous groups have now validated high-throughput approaches to autoantibody profiling in a variety of systems. Recently, we have used autoantigen microarray technology to identify distinct autoantibody profiles in H-2 congenic MRL/lpr mice (Sekine et al., manuscript in preparation), and we are expanding this platform to study human and mouse models of IDDM and RA. We are also developing protein arrays for multiplex analysis of serum antibody isotypes. Multiplexed methods for autoantibody profiling will undoubtedly continue to uncover novel aspects of autoimmunity and B cell biology. It is now time to move these technologies beyond the proof-of-concept phase, and start addressing the next series of important questions. These include, but certainly are not limited to: identifying "autoantibody signatures" associated with disease state or outcome; profiling autoantibodies during the natural course of murine and human disease; and monitoring changes in autoantibody profiles of patients in response to therapeutic intervention. However, the next set of challenges is just right around the corner. As data and statistical analysis tools become more robust, it will be possible to generate and approach new hypotheses at an unprecedented pace.

Abstract

The immune system and the nervous system maintain extensive communication, including 'hardwiring' of sympathetic and parasympathetic nerves to lymphoid organs. Neurotransmitters such as acetylcholine, norepinephrine, vasoactive intestinal peptide, substance P and histamine modulate immune activity. Neuroendocrine hormones such as corticotropin-releasing factor, leptin and alpha-melanocyte stimulating hormone regulate cytokine balance. The immune system modulates brain activity, including body temperature, sleep and feeding behavior. Molecules such as the major histocompatibility complex not only direct T cells to immunogenic molecules held in its cleft but also modulate development of neuronal connections. Neurobiologists and immunologists are exploring common ideas like the synapse to understand properties such as memory that are shared in these two systems.

Abstract

3-Hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors (ie, statins) are oral cholesterol-lowering drugs. Statins are well tolerated and have an excellent safety record. These agents competitively inhibit HMG CoA reductase, which is the enzyme that catalyzes the conversion of HMG CoA to L-mevalonate. Although L-mevalonate is a key intermediate in cholesterol synthesis, several of its metabolites are involved in post-translational modification of specific proteins involved in cell proliferation and differentiation. Thus, independent of their cholesterol-reducing properties, statins have important pleiotropic biologic effects. Recent reports indicate that statins have anti-inflammatory and neuroprotective properties. Whether statins will be of clinical benefit for patients with multiple sclerosis and other neurodegenerative diseases of the central nervous system will only be known after they are evaluated in prospective randomized clinical trials.

Abstract

Multiple sclerosis (MS) and other autoimmune diseases result from the dysregulation of genetic and proteomic programs. In MS, the loss of immune homeostasis leads to aberrant targeting and destruction of the myelin sheath, which manifests as the clinical syndrome of MS. The advent of technologies to perform large-scale analysis of mRNA transcript and protein expression will transform our understanding of the mechanisms underlying the initiation and progression of MS, and will yield new targets for therapeutic intervention.

Abstract

Bacterial DNA and immunostimulatory CpG oligodeoxynucleotides (ODNs) activate the innate immune system to produce proinflammatory cytokines. Shown to be potent Th1-like adjuvants, stimulatory CpG motifs are currently used as effective therapeutic vaccines for various animal models of infectious diseases, tumors, allergies, and autoimmune diseases. In this study, we show that the application of an immunomodulatory GpG ODN, with a single base switch from CpG to GpG, can effectively inhibit the activation of Th1 T cells associated with autoimmune disease. Moreover, this immunomodulatory GpG ODN suppresses the severity of experimental autoimmune encephalomyelitis in mice, a prototypic Th1-mediated animal disease model for multiple sclerosis.

Abstract

3-hydroxy-3-methyglutaryl coenzyme A (HMG-CoA) reductase inhibitors, 'statins' are widely used oral cholesterol-lowering drugs. Statins competitively inhibit HMG-CoA reductase, the enzyme that catalyzes conversion of HMG-CoA to L-mevalonate, a key intermediate in cholesterol synthesis. Certain metabolites of mevalonate are also involved in posttranslational modification of specific proteins involved in cell proliferation and differentiation. Thus, statins have important biologic effects that may be independent of their cholesterol-reducing properties. Recent studies indicate that statins have antiinflammatory and neuroprotective properties which may be beneficial in the treatment of multiple sclerosis as well as other central nervous system (CNS) neurodegenerative diseases. This article will outline current experimental evidence that may suggest potential clinical benefits for patients with CNS autoimmune disorders. Ultimately, clinical trials will have to determine the safety and efficacy of statins in this patient population.

Abstract

Protein arrays provide a powerful approach to study autoimmune disease. Autoimmune responses activate B cells to produce autoantibodies that recognize self-molecules termed autoantigens, many of which are proteins or protein complexes. Protein arrays enable profiling of the specificity of autoantibody responses against panels of peptides and proteins representing known autoantigens as well as candidate autoantigens. In addition to identifying autoantigens and mapping immunodominant epitopes, proteomic analysis of autoantibody responses will further enable diagnosis, prognosis, and tailoring of antigen-specific tolerizing therapy.

Abstract

Multiple sclerosis (MS) is a CNS-demyelinating disease characterised by relapsing and chronic neurological impairment. While traditionally CNS autoantigen-specific CD4(+) T cells have been considered the culprits in the initial phase of the disease, recent observations have altered this concept. It is now recognised that other T lymphocyte subclasses can initiate CNS demyelination. In addition, other cell types and molecules may play an important role in MS pathogenesis. There is overwhelming evidence that MS is a dynamic process, in which recurrent episodes of blood-brain barrier disruption and CNS inflammation play a crucial role in early disease stages, leading eventually to the largely irreversible changes of demyelination, gliosis and axonal degeneration. These observations may have important therapeutic implications. Within the last ten years, several medications have been approved for MS treatment. These agents, all of which are given parenterally, are only partially effective and are often associated with adverse effects and potential toxicities. The number and different types of medications used for MS are likely to increase in the near future, as several novel therapies are currently tested in clinical trials. 3-hydroxy-3-methyglutaryl coenzyme A reductase inhibitors, 'statins', are cholesterol-lowering drugs that are given orally, are safe and have biological effects independent of their cholesterol-reducing properties. Recent reports have shown that statins have anti-inflammatory and neuroprotective properties that may be beneficial in the treatment of MS. This article will outline experimental evidence that suggests potential clinical benefits of statins for MS patients.

Abstract

The diversity of autoimmune responses poses a formidable challenge to the development of antigen-specific tolerizing therapy. We developed 'myelin proteome' microarrays to profile the evolution of autoantibody responses in experimental autoimmune encephalomyelitis (EAE), a model for multiple sclerosis (MS). Increased diversity of autoantibody responses in acute EAE predicted a more severe clinical course. Chronic EAE was associated with previously undescribed extensive intra- and intermolecular epitope spreading of autoreactive B-cell responses. Array analysis of autoantigens targeted in acute EAE was used to guide the choice of autoantigen cDNAs to be incorporated into expression plasmids so as to generate tolerizing vaccines. Tolerizing DNA vaccines encoding a greater number of array-determined myelin targets proved superior in treating established EAE and reduced epitope spreading of autoreactive B-cell responses. Proteomic monitoring of autoantibody responses provides a useful approach to monitor autoimmune disease and to develop and tailor disease- and patient-specific tolerizing DNA vaccines.

Abstract

Multiple sclerosis (MS) is an autoimmune central nervous system (CNS) demyelinating disease that causes relapsing and chronic neurologic impairment. Recent observations have altered certain traditional concepts regarding MS pathogenesis. A greater diversity of cell types and molecules involved in MS is now evident. While remyelination can occur during the early inflammatory phase when damage may be reversible, it is impaired in the later stages, which involve axonal death. These observations have important therapeutic implications.

Abstract

Osteopontin (OPN), also known as early T-cell activating gene (Eta-1), has been recently shown to be a critical factor in the progression of experimental autoimmune encephalomyelitis, and perhaps multiple sclerosis (MS). Here we investigated whether the 327T/C, 795C/T, 1128A/G or 1284A/C single-nucleotide polymorphisms in the OPN gene were correlated with susceptibility or any of the several clinical end points in a cohort of 821 MS patients. Overall, we observed no evidence of genetic association between the OPN polymorphisms and MS. Although not reaching statistical significance, a modest trend for association with disease course was detected in patients carrying at least one wild-type 1284A allele, suggesting an effect on disease course. Patients with this genotype were less likely to have a mild disease course and were at increased risk for a secondary-progressive clinical type.

Abstract

Multiple sclerosis is a central nervous system inflammatory demyelinating disease that is thought to have an autoimmune pathogenesis. Recent results indicate that 'statins', 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, which are the most commonly used oral cholesterol-lowering drugs, have immunomodulatory properties. In this article we will review those findings that indicate that statins may be beneficial in the treatment of multiple sclerosis, neurodegenerative disease, and ischemic stroke.It was reported that statin treatment could either inhibit or reverse chronic and relapsing experimental autoimmune encephalomyelitis, a model of multiple sclerosis. Several immunomodulatory properties of statins may account for their beneficial clinical effect: Statins decreased the migration of leukocytes into the central nervous system, inhibited MHC class II and costimulatory signals required for activation of proinflammatory T cells, induced a T(H)2 phenotype in T cells, and decreased the expression of inflammatory mediators in the central nervous system, including nitric oxide and tumor necrosis factor alpha. It was also demonstrated that statin use significantly reduced beta-amyloid secretion in the cerebrospinal fluid of experimental animals. Clinically, there is emerging evidence that statins have beneficial effects in patients with multiple sclerosis, Alzheimer's disease, and ischemic stroke.In-vitro studies have indicated that statins may have anti-inflammatory properties. Results from in-vivo animal models suggest that statins may be beneficial in treatment of different central nervous system conditions. Larger scale, randomized, double-blind trials are needed to validate the role of statins as a treatment of inflammatory central nervous system diseases.

Abstract

Large-scale analyses of messenger RNA transcripts and autoantibody responses, taken from the actual sites of disease, provide us with an unprecedented view of the complexity of autoimmunity. Despite an appreciation of the large number of pathways and pathological processes that are involved in these diseases, a few practical targets and several new strategies have emerged from these studies. This review focuses on multiple sclerosis and on the approaches that are being used to identify new targets that might be manipulated to control this disease.

Abstract

Insulin dependent (i.e., "type 1") diabetes mellitus (T1DM) is considered to be a T cell mediated disease in which TH1 and Tc autoreactive cells attack the pancreatic islets. Among the beta-cell antigens implicated in T1DM, glutamic acid decarboxylase (GAD) 65 appears to play a key role in the development of T1DM in humans as well as in non-obese diabetic (NOD) mice, the experimental model for this disease. It has been shown that shifting the immune response to this antigen from TH1 towards TH2, via the administration of GAD65 peptides to young NOD mice, can suppress the progression to overt T1DM. Accordingly, various protocols of "peptide immunotherapy" of T1DM are under investigation. However, in mice with experimental autoimmune encephalomyelitis (EAE), another autoimmune TH1 mediated disease that mimics human multiple sclerosis, anaphylactic shock can occur when the mice are challenged with certain myelin self peptides that initially were administered with adjuvant to induce the disease.Here we show that NOD mice, that spontaneously develop T1DM, can develop fatal anaphylactic reactions upon challenge with preparations of immunodominant GAD65 self peptides after immunization with these peptides to modify the development of T1DM.These findings document severe anaphylaxis to self peptide preparations used in an attempt to devise immunotherapy for a spontaneous autoimmune disease. Taken together with the findings in EAE, these results suggest that peptide therapies designed to induce a TH1 to TH2 shift carry a risk for the development of anaphylactic reactivity to the therapeutic peptides.

Abstract

Molecular cloning, sequencing of the human genome, and other major advances in biomedical research have contributed substantially to our understanding of autoimmune disease. Nevertheless, to date, such advances have failed to reveal the etiology of or yield curative therapies for autoimmune disease. New approaches are needed. Proteomics, the large-scale study of expression and function of proteins that compose our tissues and mediate disease, represents a powerful and promising strategy. We developed protein and peptide arrays to profile autoantibody responses in autoimmune disease. Protein and peptide array analysis of autoimmune samples is revealing human and pathogen proteins involved in initiation and perpetuation of autoimmunity. Proteomic determination of autoantibody profiles can be utilized for diagnosis, prognostication, and guiding tolerizing therapy for autoimmune disease.

Abstract

Pharmacotherapy for relapsing-remitting multiple sclerosis (MS) advanced with the demonstration that interferon beta and glatiramer acetate improve the clinical course of this disease. Mitoxantrone is the first drug approved by the Food and Drug Administration for treatment of secondary progressive MS. Despite this progress, the agents presently available are only partially effective, are difficult to administer, and may have significant side effects. Several orally administered immunomodulatory agents are presently being evaluated for treatment of MS. One class of drugs, HMG CoA inhibitors (statins), is safe and well-tolerated and could become another mainstay of MS therapy.This article reviews the clinical evidence for approved MS therapies and discusses their mechanisms of action. Furthermore, the clinical and laboratory data suggesting a potential role for statins in MS therapy are discussed.Although treatment with interferon beta, glatiramer acetate, and mitoxantrone, the approved therapies, provide important treatment options for patients with relapsing-remitting MS and secondary progressive MS, the potential benefits of other medications, including statins, should be explored in controlled clinical trials.

Abstract

Women with multiple sclerosis have significantly diminished disease activity during pregnancy. The purpose of our study was to identify the underlying mechanism for the diminished disease activity. We found that during the period of late pregnancy there is protection against paralysis, during both the induction and effector phases of relapsing experimental autoimmune encephalomyelitis, a mouse model of multiple sclerosis. We did not find any changes in the cytokine secretion profiles or the proliferative activity of autoreactive T cells from mice induced during late pregnancy compared with virgin controls. In mice mated after disease onset, the inflammatory histologic lesions did not clear, despite marked clinical improvement during pregnancy. We found evidence for a serum factor present in late pregnancy that suppresses T cell activation. In the presence of sera taken from mice late in pregnancy, the proliferative response and IL-2 production of proteolipid protein p139-151-specific T cells were significantly diminished as compared with stimulation in the presence of normal mouse sera. In conclusion, serum from late pregnancy has the capacity to down-regulate T cell responses and might be associated with the amelioration of disease activity in experimental autoimmune encephalomyelitis.

Abstract

The development of vaccines is arguably the most significant achievement in medicine to date. The practice of innoculation with the fluid from a sore to protect from a disease actually dates back to ancient China; however, with the introduction of Jenner's smallpox vaccine, and greater understanding of the immune system, vaccines have become specific and systematic. Traditional vaccines have used killed pathogens (hepatitis A and the Salk polio vaccines), immunogenic subunits of a given pathogen (hepatitis B subunit vaccine), or live attenuated pathogens (measles, mumps, rubella, Sabin polio vaccines) to generate protective immunity. Currently, a new generation of vaccines that use the genetic material of a pathogen to elicit protective immunity are being developed. Although the most widespread and successful use of vaccines today remains in the arena of infectious diseases, manipulations of immune responses to protect against cancers, neurologic diseases, and autoimmunity are being explored rigorously.

Abstract

Microarray analysis of multiple sclerosis (MS) lesions obtained at autopsy revealed increased transcripts of genes encoding inflammatory cytokines, particularly interleukin-6 and -17, interferon-gamma and associated downstream pathways. Comparison of two poles of MS pathology--acute lesions with inflammation versus 'silent' lesions without inflammation--revealed differentially transcribed genes. Some products of these genes were chosen as targets for therapy of experimental autoimmune encephalomyelitis (EAE) in mice. Granulocyte colony-stimulating factor is upregulated in acute, but not in chronic, MS lesions, and the effect on ameliorating EAE is more pronounced in the acute phase, in contrast to knocking out the immunoglobulin Fc receptor common gamma chain where the effect is greatest on chronic disease. These results in EAE corroborate the microarray studies on MS lesions. Large-scale analysis of transcripts in MS lesions elucidates new aspects of pathology and opens possibilities for therapy.

Abstract

Autoimmune disease affects 3% of the world population, yet current therapies that globally suppress immune function are inadequate. Tremendous need exists for specific and curative therapies, and we describe a strategy for development of antigen-specific therapies that inactivate pathogenic lymphocytes causing tissue injury. Major barriers to development of antigen-specific therapies for T-cell-mediated autoimmune diseases, such as multiple sclerosis, rheumatoid arthritis, and autoimmune diabetes, include (i) lack of knowledge of the specificity of autoimmune responses, for which proteomic technologies represent powerful tools to identify the self-protein targets of the autoimmune response, and (ii) lack of methods to induce specific immune tolerance, for which DNA tolerizing vaccines represent a promising strategy. We termed our approach Reverse Genomics: use of the proteomics-determined specificity of the autoantibody response to develop and select DNA tolerizing vaccines. Studies performed using animal models for multiple sclerosis and autoimmune diabetes support our Reverse Genomics approach. Through integration of proteomics with specific tolerizing therapies, we are developing a comprehensive approach to treat human autoimmune disease.

Abstract

We constructed miniaturized autoantigen arrays to perform large-scale multiplex characterization of autoantibody responses directed against structurally diverse autoantigens, using submicroliter quantities of clinical samples. Autoantigen microarrays were produced by attaching hundreds of proteins, peptides and other biomolecules to the surface of derivatized glass slides using a robotic arrayer. Arrays were incubated with patient serum, and spectrally resolvable fluorescent labels were used to detect autoantibody binding to specific autoantigens on the array. We describe and characterize arrays containing the major autoantigens in eight distinct human autoimmune diseases, including systemic lupus erythematosus and rheumatoid arthritis. This represents the first report of application of such technology to multiple human disease sera, and will enable validated detection of antibodies recognizing autoantigens including proteins, peptides, enzyme complexes, ribonucleoprotein complexes, DNA and post-translationally modified antigens. Autoantigen microarrays represent a powerful tool to study the specificity and pathogenesis of autoantibody responses, and to identify and define relevant autoantigens in human autoimmune diseases.

Abstract

An expanded polyglutamine domain in huntingtin underlies the pathogenic events in Huntington disease (HD), characterized by chorea, dementia and severe weight loss, culminating in death. Transglutaminase (TGase) may be critical in the pathogenesis, via cross-linking huntingtin. Administration of the TGase competitive inhibitor, cystamine, to transgenic mice expressing exon 1 of huntingtin containing an expanded polyglutamine repeat, altered the course of their HD-like disease. Cystamine given intraperitoneally entered brain where it inhibited TGase activity. When treatment began after the appearance of abnormal movements, cystamine extended survival, reduced associated tremor and abnormal movements and ameliorated weight loss. Treatment did not influence the appearance or frequency of neuronal nuclear inclusions. Unexpectedly, cystamine treatment increased transcription of one of the two genes shown to be neuroprotective for polyglutamine toxicity in Drosophila, dnaj (also known as HDJ1 and Hsp40 in humans and mice, respectively). Inhibition of TGase provides a new treatment strategy for HD and other polyglutamine diseases.

Abstract

Transglutaminase (TGase) activity is increased in affected regions of brains from patients with Huntington's disease (HD). TGase activity is particularly elevated in the nucleus compared with the cytoplasm from these brains. Gamma-glutaminyl-lysyl cross-links have been detected in nuclear inclusions in HD brain, indicating that TGase may play a prominent role in the aggregation of huntingtin (htt). Attempts to ameliorate experimental disease, via inhibition of TGase in transgenic models of HD in mice, are under investigation.

Abstract

Proteomics technologies enable profiling of autoantibody responses using biological fluids derived from patients with autoimmune disease. They provide a powerful tool to characterize autoreactive B-cell responses in diseases including rheumatoid arthritis, multiple sclerosis, autoimmune diabetes, and systemic lupus erythematosus. Autoantibody profiling may serve purposes including classification of individual patients and subsets of patients based on their 'autoantibody fingerprint', examination of epitope spreading and antibody isotype usage, discovery and characterization of candidate autoantigens, and tailoring antigen-specific therapy. In the coming decades, proteomics technologies will broaden our understanding of the underlying mechanisms of and will further our ability to diagnose, prognosticate and treat autoimmune disease.

Abstract

Recent technological breakthroughs allowing for large-scale analysis of gene transcripts and large-scale monitoring of the immune response with protein chips are revealing new participants in the pathogenesis of multiple sclerosis. Some of these participants may be useful targets for therapy.

Abstract

Pathological-length polyglutamine (Q(n)) expansions, such as those that occur in the huntingtin protein (htt) in Huntington's disease (HD), are excellent substrates for tissue transglutaminase in vitro, and transglutaminase activity is increased in post-mortem HD brain. However, direct evidence for the participation of tissue transglutaminase (or other transglutaminases) in HD patients in vivo is scarce. We now report that levels of N(epsilon)-(gamma-L-glutamyl)-L-lysine (GGEL)--a 'marker' isodipeptide produced by the transglutaminase reaction--are elevated in the CSF of HD patients (708 +/- 41 pmol/mL, SEM, n = 36) vs. control CSF (228 +/- 36, n = 27); p < 0.0001. These data support the hypothesis that transglutaminase activity is increased in HD brain in vivo.

Abstract

Multiple sclerosis is a demyelinating disease, characterized by inflammation in the brain and spinal cord, possibly due to autoimmunity. Large-scale sequencing of cDNA libraries, derived from plaques dissected from brains of patients with multiple sclerosis (MS), indicated an abundance of transcripts for osteopontin (OPN). Microarray analysis of spinal cords from rats paralyzed by experimental autoimmune encephalomyelitis (EAE), a model of MS, also revealed increased OPN transcripts. Osteopontin-deficient mice were resistant to progressive EAE and had frequent remissions, and myelin-reactive T cells in OPN-/- mice produced more interleukin 10 and less interferon-gamma than in OPN+/+ mice. Osteopontin thus appears to regulate T helper cell-1 (TH1)-mediated demyelinating disease, and it may offer a potential target in blocking development of progressive MS.

Immunotherapy of multiple sclerosis: the end of the beginningCURRENT OPINION IN IMMUNOLOGYSteinman, L.2001; 13 (5): 597-600

Abstract

Currently available medicines approved for use in Europe and North America reduce the relapse rate in relapsing/remitting multiple sclerosis by about 30%. These medications may be no more efficacious than intermittent use of corticosteroids at the time of relapse. New directions for therapy of multiple sclerosis include blockade of alpha4 integrin, the use of altered peptide ligands, inhibition of Th1 cytokines, and DNA vaccination.

Abstract

T cell-mediated destruction of the myelin sheath causes inflammatory damage of the CNS in multiple sclerosis (MS). The major T and B cell responses in MS patients who are HLA-DR2 (about two-thirds of MS patients) react to a region between residues 84 and 103 of myelin basic protein (1 ). The crystal structure of HLA-DR2 complexed with myelin basic protein(84-102) confirmed that Lys(91) is the major TCR contact site, whereas Phe(90) is a major anchor to MHC and binds the hydrophobic P4 pocket (2 ). We have tested peptides containing repetitive 4-aa sequences designed to bind critical MHC pockets and to interfere with T cell activation. One such sequence, EYYKEYYKEYYK, ameliorates experimental autoimmune encephalomyelitis in Lewis rats, an animal model of MS.

Abstract

Spinal cord injury results in a massive loss of neurons, and thus of function. We recently reported that passive transfer of autoimmune T cells directed against myelin-associated antigens provides acutely damaged spinal cords with effective neuroprotection. The therapeutic time window for the passive transfer of T cells was found to be at least 1 week. Here we show that posttraumatic T cell-based active vaccination is also neuroprotective. Immunization with myelin-associated antigens such as myelin basic protein (MBP) significantly promoted recovery after spinal cord contusion injury in the rat model. To reduce the risk of autoimmune disease while retaining the benefit of the immunization, we vaccinated the rats immediately after severe incomplete spinal cord injury with MBP-derived altered peptide ligands. Immunization with these peptides resulted in significant protection from neuronal loss and thus in a reduced extent of paralysis, assessed by an open-field behavioral test. Retrograde labeling of the rubrospinal tracts and magnetic resonance imaging supported the behavioral results. Further optimization of nonpathogenic myelin-derived peptides can be expected to lead the way to the development of an effective therapeutic vaccination protocol as a strategy for the prevention of total paralysis after incomplete spinal cord injury.

Abstract

DNA vaccination is an effective means of protecting experimental animals against infectious pathogens and cancer and has more recently been used to prevent autoimmune disease. Insulin-dependent diabetes mellitus (IDDM) is an autoimmune disease characterized by T-cell-mediated destruction of the insulin-secreting beta cells in the pancreas. The NOD mouse is an animal model of IDDM in which several autoantigens, including insulin, have been identified. In this study we demonstrate that vaccination of NOD mice with DNA encoding an immunodominant peptide of insulin (residues 9-23 of the B chain) protects the animals from developing diabetes. Animals injected intramuscularly with a bacterial plasmid encoding the insulin B chain peptide show significantly lower disease incidence and delayed onset of disease when compared to controls. Protection appears to be mediated by insulin B (9-23)-specific down-regulation of IFN-gamma. Our results confirm that DNA vaccination has a protective effect on autoimmunity, the understanding of which will reveal new insights into the immune system and open doors for novel therapies.

Abstract

Using a combination of local gene delivery and tolerizing DNA vaccination, we demonstrate that codelivery of the interleukin-4 (IL-4) gene and a DNA vaccine encoding the self-peptide proteolipid protein 139-151 (PLP139-151) provides protective immunity against experimental autoimmune encephalomyelitis (EAE). We provide evidence for a mechanism whereby IL-4 expressed from the naked DNA is secreted and acts locally on autoreactive T cells via activation of STAT6 to shift their cytokine profile to T helper 2. We also show that DNA vaccines can be used to reverse established EAE by covaccination with the genes for myelin oligodendrocyte glycoprotein and IL-4. This treatment strategy combines the antigen-specific effects of DNA vaccination and the beneficial effects of local gene delivery.

Abstract

This unit describes the use of PCR to characterize and quantify rearranged transcripts from specific T cell receptor variable gene families in human tissue and peripheral blood lymphocytes. The strategy outlined in this unit has been extensively used on different sources of human tissue including brain, spinal cord, and skeletal muscle. A protocol is provided to clone and sequence PCR-amplified cDNA transcripts to study the junctional diversity of the expressed genes. A support protocol describes a method for reverse transcribing total RNA to make the cDNA required by the other protocols.

Abstract

The development of antigen specific therapy for multiple sclerosis (MS) involves specifically suppressing undesired immune responses targeting the myelin sheath and underlying axon. We have recently reported some success with altered peptide ligands for a major target of the autoimmune response in MS. Antigen specific therapy has the potential to suppress undesirable autoimmunity, while leaving the rest of the immune system intact. Induction of an antigen specific Th1-to-Th2 shift could achieve this aim, once side effects, such as allergic responses, are minimized with optimal dosing.

Abstract

EAE can refer either to experimental autoimmune encephalomyelitis or experimental allergic encephalomyelitis. Although EAE is classically a prototypic T helper 1 (TH1) cell-mediated autoimmune disease, it can also be induced by TH2 cells. Characteristically, the most severe manifestation of allergy, anaphylaxis, is associated with exposure to a foreign antigen that is often derived from medication, insect venom or food. We report here that, after self-tolerance to myelin is destroyed, anaphylaxis may be triggered by a self-antigen, in this case a myelin peptide. "Horror autotoxicus", which was initially described by Ehrlich, may not only include autoimmunity to self, it may also encompass immediate hypersensitivity to self, which leads to shock and rapid death.

The design, synthesis, and evaluation of molecules that enable or enhance cellular uptake: Peptoid molecular transportersPROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICAWender, P. A., Mitchell, D. J., Pattabiraman, K., Pelkey, E. T., Steinman, L., Rothbard, J. B.2000; 97 (24): 13003-13008

Abstract

Certain proteins contain subunits that enable their active translocation across the plasma membrane into cells. In the specific case of HIV-1, this subunit is the basic domain Tat(49-57) (RKKRRQRRR). To establish the optimal structural requirements for this translocation process, and thereby to develop improved molecular transporters that could deliver agents into cells, a series of analogues of Tat(49-57) were prepared and their cellular uptake into Jurkat cells was determined by flow cytometry. All truncated and alanine-substituted analogues exhibited diminished cellular uptake, suggesting that the cationic residues of Tat(49-57) play a principal role in its uptake. Charge alone, however, is insufficient for transport as oligomers of several cationic amino acids (histidine, lysine, and ornithine) are less effective than Tat(49-57) in cellular uptake. In contrast, a 9-mer of l-arginine (R9) was 20-fold more efficient than Tat(49-57) at cellular uptake as determined by Michaelis-Menton kinetic analysis. The d-arginine oligomer (r9) exhibited an even greater uptake rate enhancement (>100-fold). Collectively, these studies suggest that the guanidinium groups of Tat(49-57) play a greater role in facilitating cellular uptake than either charge or backbone structure. Based on this analysis, we designed and synthesized a class of polyguanidine peptoid derivatives. Remarkably, the subset of peptoid analogues containing a six-methylene spacer between the guanidine head group and backbone (N-hxg), exhibited significantly enhanced cellular uptake compared to Tat(49-57) and even to r9. Overall, a transporter has been developed that is superior to Tat(49-57), protease resistant, and more readily and economically prepared.

Abstract

Homopolymers or peptides containing a high percentage of cationic amino acids have been shown to have a unique ability to cross the plasma membrane of cells, and consequently have been used to facilitate the uptake of a variety of biopolymers and small molecules. To investigate whether the polycationic character of these molecules, or some other structural feature, was the molecular basis for the effect, the ability of a variety of homopolymers to enter cells was assayed by confocal microscopy and flow cytometry. Polymers of L- or D-arginine containing six or more amino acids entered cells far more effectively than polymers of equal length composed of lysine, ornithine and histidine. Peptides of fewer than six amino acids were ineffective. The length of the arginine side-chain could be varied without significant loss of activity. These data combined with the inability of polymers of citrulline to enter cells demonstrated that the guanidine headgroup of arginine was the critical structural component responsible for the biological activity. Cellular uptake could be inhibited by preincubation of the cells with sodium azide, but not by low temperature (3 degrees C), indicating that the process was energy dependent, but did not involve endocytosis.

Abstract

In this 'double-blind', randomized, placebo-controlled phase II trial, we compared an altered peptide ligand of myelin basic protein with placebo, evaluating their safety and influence on magnetic resonance imaging in relapsing-remitting multiple sclerosis. A safety board suspended the trial because of hypersensitivity reactions in 9% of the patients. There were no increases in either clinical relapses or in new enhancing lesions in any patient, even those with hypersensitivity reactions. Secondary analysis of those patients completing the study showed that the volume and number of enhancing lesions were reduced at a dose of 5 mg. There was also a regulatory type 2 T helper-cell response to altered peptide ligand that cross-reacted with the native peptide.

Despite epitope spreading in the pathogenesis of autoimmune disease, highly restricted approaches to immune therapy may still succeed [with a hedge on this bet]JOURNAL OF AUTOIMMUNITYSteinman, L.2000; 14 (4): 278-282

Abstract

The expression of leukocyte adhesion molecules in the intact brains of mice with experimental autoimmune encephalitis (EAE) was visualized by Magnetic Resonance Imaging (MRI) through the use of a new, target-specific MR contrast agent. Antibody-conjugated paramagnetic liposomes (ACPLs) were designed to achieve in vivo targeting of molecules expressed on vascular endothelium, while providing sufficient signal enhancement at these sites for detection by MRI. ACPLs targeted to intercellular adhesion molecule-1 (ICAM-1), an endothelial leukocyte receptor upregulated on cerebral microvasculature during EAE, were administered to diseased mice. Fluorescence microscopy confirmed that fluorescently-tagged ACPLs were localized to central nervous system (CNS) microvasculature in a pattern consistent with ICAM-1 upregulation described immunohistochemically. High resolution MRI of mouse brains ex vivo demonstrated that ACPL binding conferred significant enhancement of signal intensity (SI) as compared to control images. These results suggest that ACPLs can be used as MRI contrast agents to visualize specific molecules expressed on vascular endothelium during disease.

Abstract

Multigenic programs controlling susceptibility to apoptosis in response to ionizing radiation have not yet been defined. Here, using DNA microarrays, we show gene expression patterns in an apoptosis-sensitive and apoptosis-resistant murine B cell lymphoma model system both before and after irradiation. From the 11,000 genes interrogated by the arrays, two major patterns emerged. First, before radiation exposure the radioresistant LYar cells expressed significantly greater levels of message for several genes involved in regulating intracellular redox potential. Compared with LYas cells, LYar cells express 20- to 50-fold more mRNA for the tetraspanin CD53 and for fructose-1,6-bisphosphatase. Expression of both of these genes can lead to the increase of total cellular glutathione, which is the principle intracellular antioxidant and has been shown to inhibit many forms of apoptosis. A second pattern emerged after radiation, when the apoptosis-sensitive LYas cells induced rapid expression of a unique cluster of genes characterized by their involvement in mitochondrial electron transport. Some of these genes have been previously recognized as proapoptotic; however others, such as uncoupling protein 2, were not previously known to be apoptotic regulatory proteins. From these observations we propose that a multigenic program for sensitivity to apoptosis involves induction of transcripts for genes participating in mitochondrial uncoupling and loss of membrane potential. This program triggers mitochondrial release of apoptogenic factors and induces the "caspase cascade." Conversely, cells resistant to apoptosis down-regulate these biochemical pathways, while activating pathways for establishment and maintenance of high intracellular redox potential by means of elevated glutathione.

Abstract

Amyotrophic lateral sclerosis (ALS) is a fatal disorder whose etiology and pathogenesis remain unknown. Recent studies, however, have demonstrated the presence of inflammatory infiltrates within ALS spinal cord and suggested the possibility of an immune-mediated process in motor neuron degeneration. We have analyzed the diversity of T-cells in the spinal cord in ALS. Reverse transcriptase polymerase chain reaction (RT-PCR) with variable (V) region sequence specific oligonucleotide primers was used to amplify T-cell receptor (TCR)BV transcripts from spinal cords obtained at autopsy from patients with ALS, patients who died without inflammatory disease of the central nervous system, brains from patients with ALS, and brains from patients who died with inflammatory CNS disease. Sequencing was then performed on the amplified transcripts. An overall increase in the level of TCRBV 2 transcripts was detected in ALS specimens when compared to controls. This result was independent of the HLA genotype of the individual. Furthermore, enrichment of TCRBV2-positive T cells could be demonstrated in cerebrospinal fluid derived from patients with ALS, using PCR analysis and a T cell stimulation assay with toxic shock syndrome toxin-1 (TSST-1), a Vbeta2-specific superantigen. Our results suggest that an immunological process involving the specific expansion of Vbeta2 TCR-positive T-cells may be important in the pathogenesis of ALS.

Abstract

The protein huntingtin (htt), aggregated in neuronal nuclear inclusions, is pathognomonic of Huntington's disease (HD). Constructs, translated in vitro from the N terminus of htt, containing either polyQ23 from a normal individual, or polyQ41 or polyQ67 from an HD patient, were all soluble. Transglutaminase (TGase) crosslinked these proteins, and the aggregations did not have the staining properties of amyloid. More TGase-catalyzed aggregates formed when the polyglutamine domain of htt exceeded the pathologic threshold of polyQ36. Furthermore, shorter htt constructs, containing 135 aa or fewer, formed more aggregates than did larger htt constructs. TGase activity in the HD brain was increased compared with the control, with notable increases in cell nuclei. The increased TGase activity was brain specific. In lymphoblastoid cells from HD patients, TGase activity was decreased. TGase-mediated crosslinking of htt may be involved in the formation of the nonamyloidogenic nuclear inclusions found in the HD brain. The staining properties of nuclear inclusions in the HD brain revealed that they were not amyloid.

Antibodies to CD44 and integrin alpha(4), but not L-selectin, prevent central nervous system inflammation and experimental encephalomyelitis by blocking secondary leukocyte recruitmentPROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICABrocke, S., Piercy, C., Steinman, L., Weissman, I. L., VEROMAA, T.1999; 96 (12): 6896-6901

Abstract

The role of various adhesion molecules in lymphocyte homing to the brain and in inflammatory autoimmune disease of the central nervous system (CNS) was examined in mice. Activated T cell lines and clones expressed CD44 and integrin alpha4, but not L-selectin, and entered the CNS independent of their antigen specificity. mAbs directed against CD44 and integrin alpha4 prevented the transfer of experimental autoimmune encephalomyelitis (EAE) by myelin basic protein-specific T cells. T cells preincubated with anti-CD44 or antiintegrin alpha4 were blocked only partially from entering the brain parenchyma. However, both antibodies efficiently prevented CNS inflammation and clinical expression of EAE when injected in vivo. This effect lasted as long as antibodies were administered. Antibodies specific for L-selectin had no effect on homing of encephalitogenic T cells to the brain or development of EAE. Antiintegrin alpha4 and anti-CD44 did not impair the activation and function of encephalitogenic T cells in vitro and did not deplete integrin alpha4- or CD44-positive cells in vivo. These data suggest that, in the absence of leukocyte recruitment, the entry of a reduced number of activated myelin basic protein-reactive T cells in the CNS is not sufficient for the development and expression of EAE. We propose that antibodies to integrin alpha4 and CD44 prevent clinical disease by partially targeting the primary influx of encephalitogenic T cells and by preventing the secondary influx of leukocytes to lesions initiated by the transferred T cells.

Abstract

Usually we rely on vaccination to promote an immune response to a pathogenic microbe. In this study, we demonstrate a suppressive from of vaccination, with DNA encoding a minigene for residues 139-151 of myelin proteolipid protein (PLP139-151), a pathogenic self-Ag. This suppressive vaccination attenuates a prototypic autoimmune disease, experimental autoimmune encephalomyelitis, which presents clinically with paralysis. Proliferative responses and production of the Th1 cytokines, IL-2 and IFN-gamma, were reduced in T cells responsive to PLP139-151. In the brains of mice that were successfully vaccinated, mRNA for IL-2, IL-15, and IFN-gamma were reduced. A mechanism underlying the reduction in severity and incidence of paralytic autoimmune disease and the reduction in Th1 cytokines involves altered costimulation of T cells; loading of APCs with DNA encoding PLP139-151 reduced the capacity of a T cell line reactive to PLP139-151 to proliferate even in the presence of exogenous CD28 costimulation. DNA immunization with the myelin minigene for PLP-altered expression of B7.1 (CD80), and B7.2 (CD86) on APCs in the spleen. Suppressive immunization against self-Ags encoded by DNA may be exploited to treat autoimmune diseases.

Abstract

Regulatory sequences used in plasmids for naked DNA vaccination can modulate cytokine production in vivo. We demonstrate here that injection of plasmid DNA can suppress the prototypic T cell-mediated autoimmune disease, experimental autoimmune encephalomyelitis, by inducing IFN-gamma.

Abstract

Experimental autoimmune encephalomyelitis (EAE) is an inflammatory autoimmune disease of the central nervous system that serves as a model for the human disease multiple sclerosis. Paralysis is "induced" by CD4+ T cells of the Th1 phenotype. Tumor necrosis factor (TNF), a Th1 type cytokine, has been shown to be upregulated in the CNS during the onset of EAE, and systemic manipulations of TNF have had substantial effects on disease progression. However, the precise role of TNF in EAE has been called into question by recent experiments utilizing TNF and lymphotoxin knockout mice. We demonstrate here that the local delivery of TNF by myelin basic protein (MBP)-specific T cells, retrovirally transduced to express TNF, exacerbated MBP-induced disease following adoptive transfer into syngeneic mice.

Abstract

Molecular mimicry has been suggested as a mode of autoreactive T cell stimulation in autoimmune diseases. Myelin basic protein (MBP) peptide 1-11 induces experimental autoimmune encephalomyelitis (EAE) in susceptible strains of mice. Here we show that a herpesvirus Saimiri (HVS) peptide, AAQRRPSRPFA, with a limited homology to MBP1-11 peptide, ASQKRPSQRHG (underlined letters showing homology), can stimulate a panel of MBP-11-specific T cell hybridomas and more importantly cause EAE in mice. We demonstrate that this is due to cross-recognition of these two peptides by TCRs. Results presented in this communication are the first demonstration that a viral peptide with homology at just 5 amino acids with a self peptide can induce clinical signs of EAE in mice. These findings have important implications in understanding the breakdown of T cell tolerance to self Ags in autoimmune diseases by means of cross-reactivity with unrelated peptides.

Abstract

The p53 molecule might serve as a common tumor-associated antigen, as the tumor suppressor gene p53 is mutated and the p53 protein is often over-expressed in tumor cells. We report that effective immunity to p53 can be induced through an idiotypic network by immunization of mice with a monoclonal antibody (PAb-240) specific for mutated p53, or with a peptide derived from the complementarity determining region (CDR) 3 of the variable domain of the light chain (VL) of this antibody. The immunized mice produced IgG antibodies to p53 and mounted a cytotoxic reaction to a tumor line bearing mutated p53. The idiotypically immunized mice were resistant to challenge with the tumor cells. Thus antibodies to p53 might serve as immunogens for activating resistance to some tumors. At the basic level, these findings indicate that a network of p53 immunity may be organized naturally within the immune system.

Abstract

An immunodominant epitope of myelin basic protein (MBP), VHFFKNIVTPRTP (p87-99), is a major target of T cells in brain lesions of multiple sclerosis (MS), and this peptide can trigger experimental autoimmune encephalomyelitis (EAE). We designed truncated peptides based on this pathogenic 13-mer that are not antigenic. These short peptides reduced production of IFN-gamma and TNF-alpha in vivo. Moreover, paraplegic rats given the 7-mer FKNIVTP in soluble form showed total reversal of paralysis in 24 h. Truncated peptides that are too small to stimulate antigenic responses to pathogenic regions of myelin basic protein are nevertheless effective tolerogens and are able to anergize autoreactive T cells. Short peptide-based tolerogens, devoid of immunogenic and pathogenic potential, may be attractive for therapy of autoimmune diseases.

Abstract

The mechanisms by which microbial peptide antigens and superantigens might initiate and perpetuate autoimmune responses against antigens of the central nervous system are discussed. A model will be proposed that includes the initial activation of naive T lymphocytes through T cell receptor-mediated recognition of microbial antigens presented by MHC class II molecules. This event might be followed by re-activation of autoreactive T cells by bacterial and viral superantigens. Both mechanisms could lead to acute and relapsing autoimmune disease.

Abstract

The ability of T cells to adhere to and interact with components of the blood vessel walls and the extracellular matrix is essential for their extravasation and migration into inflamed sites. We have found that the beta1 integrin-mediated adhesion of resting human T cells to fibronectin, a major glycoprotein component of the extracellular matrix, is induced by physiologic concentrations of three neuropeptides: calcitonin gene-related protein (CGRP), neuropeptide Y, and somatostatin; each acts via its own specific receptor on the T cell membrane. In contrast, substance P (SP), which coexists with CGRP in the majority of peripheral endings of sensory nerves, including those innervating the lymphoid organs, blocks T cell adhesion to fibronectin when induced by CGRP, neuropeptide Y, somatostatin, macrophage inflammatory protein-1beta, and PMA. Inhibition of T cell adhesion was obtained both by the intact SP peptide and by its 1-4 N-terminal and its 4-11, 5-11, and 6-11 C-terminal fragments, used at similar nanomolar concentrations. The inhibitory effects of the parent SP peptide and its fragments were abrogated by an SP NK-1 receptor antagonist, suggesting they all act through the same SP NK-1 receptor. These findings suggest that neuropeptides, by activating their specific T cell-expressed receptors, can provide the T cells with both positive (proadhesive) and negative (antiadhesive) signals and thereby regulate their function. Thus, neuropeptides may influence diverse physiologic processes involving integrins, including leukocyte-mediated migration and inflammation.

Abstract

The discovery that functionally heterogeneous CD4+ T-cell subsets secrete different cytokines offers an explanation for the ability of certain T cells to mediate a predominant cell-mediated immune response versus a humoral response often accompanied by allergic manifestations. Th1 cells, important for cell-mediated immunity by their production of IL-2, IFN-gamma and lymphotoxin, have been implicated in the immunopathology of certain organ-specific autoimmune diseases whereas a role as regulators has been suggested for IL-4 and IL-10 producing Th2 cells. Recent findings, however, beg re-evaluation of the direct role of Th2 cells in the induction or maintenance of tolerance, whereas evidence for the role of a distinct subset of regulatory T cells producing TGF-beta to suppress cell-mediated immunopathology is compelling.

Abstract

Myelin basic protein (MBP) may be an important autoantigen in multiple sclerosis (MS), with the MBP(82-100) region being immunodominant for T cells and autoantibodies. The structural requirements for autoantibody recognition were compared to those previously defined for MBP-specific T cell clones. MBP autoantibodies were affinity-purified from central nervous system lesions of 11/12 postmortem cases studied. The MBP(83-97) peptide was immunodominant in all 11 cases since it inhibited autoantibody binding to MBP > 95%. Residues contributing to autoantibody binding were located in a 10-amino acid segment (V86-T95) that also contained the MHC/T cell receptor contact residues of the T cell epitope. In the epitope center, the same residues were important for antibody binding and T cell recognition. Based on the antibody-binding motif, microbial peptides were identified that were bound by purified autoantibodies. Autoantibody binding of microbial peptides required sequence identity at four or five contiguous residues in the epitope center. Microbial peptides previously found to activate T cell clones did not have such obvious homology to MBP since sequence identity was not required at MHC contacts. The similar fine specificity of B cells and T cells may be useful for tolerance induction to MBP in MS.

Abstract

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS), characterized by accumulation of mononuclear cells. The pathogenesis of MS is complex and probably involves soluble immune mediators, particularly cytokines, and activated memory T cells, that are thought to migrate into the CNS. During lesion formation in MS, cytokines regulate cell functions, such as cell recruitment and migration. Because the chemokine RANTES play a role in both activating and recruiting leucocytes, particularly memory T cells into inflammatory sites, the authors have assessed RANTES mRNA levels at the site of lesions. Expression levels were analysed in brain samples and compared with neurological, infectious and other controls. RANTES was expressed by activated perivascular memory T cells, predominantly located at the edge of active plaques. While RANTES mRNA was detected in all 17 MS brains analysed, it was only found in six of the 14 control patients and generally at a lower expression level. In view of the regulatory and chemotactic properties of RANTES, these results imply that RANTES in MS lesions may play an important role in the activation and/or selective accumulation of memory T cells and, thereby, in the pathogenic events associated with MS.

Abstract

Corticotropin-releasing factor (CRF) exerts a major role in the stress response. Both CRF and urocortin, a newly discovered neuropeptide homologous to CRF, suppressed experimental autoimmune encephalomyelitis (EAE). Suppression of paralysis with CRF involved stimulation of the hypothalamic-pituitary-adrenal axis and inhibitory effects on an encephalitogenic T cell line. While CRF increased glucocorticoid production, which is known to block EAE, it also suppressed EAE in adrenalectomized rats, where glucocorticoid stimulation via CRF plays no role. Moreover, the encephalitogenicity of a T cell line exposed to CRF in vitro was reduced. Stress may influence autoimmune disease through the hypothalamic-pituitary-adrenal axis and directly via the immune system.

Abstract

DNA vaccines offer a unique means of stimulating and enhancing the immune response. Subjects are vaccinated with the gene for a particular antigen rather than with the antigen itself--the foreign protein that elicits the response is made intracellularly. This new type of gene therapy may not only extend the limits of immunoprotection but may also provide new insight into microbiologic and immunologic processes.

Abstract

Experimental autoimmune encephalomyelitis (EAE) is an inflammatory autoimmune disease of the central nervous system which serves as a model for the human disease multiple sclerosis. We demonstrate here that encephalitogenic T cells, transduced with a retroviral gene, construct to express interleukin 4, and can delay the onset and reduce the severity of EAE when adoptively transferred to myelin basic protein-immunized mice. Thus, T lymphocytes transduced with retroviral vectors can deliver "regulatory cytokines" in a site-specific manner and may represent a viable therapeutic strategy for the treatment of autoimmune disease.

Abstract

Several regions of the human genome are associated with susceptibility to multiple sclerosis (MS). We review studies of linkage of MS to germline genes using microsatellites. A modest effect on susceptibility was seen with markers in the vicinity of 6p21 (HLA) and 17q22. The influence of epistatic interactions between these genes is considered. The impact of genetic rearrangements of certain germline genes on susceptibility to MS is described. Analysis of TCR gene rearrangements has established some of the target antigens of the immune response in MS. Environmental influences on MS are described with particular attention given to how microbes might trigger demyelinating disease.

Abstract

Experimental autoimmune encephalomyelitis (EAE) in an inflammatory demyelinating disease which usually follows a monophasic course. Autoreactive Th1 CD4+ T cells are responsible for the lesions, whereas autoreactive Th2 CD4+ T cells can, upon adoptive transfer, suppress the disease process. However, the role of IL-4 and Th2 cells in the spontaneous remission of EAE and in the prevention of relapses is not known. We have addressed these issues using IL-4-deficient mice in which the differentiation of Th2 CD4+ T cells is severely compromised. The clinical course of actively induced EAE was compared in IL-4+/+, IL-4+ /- and IL-4-/- mice on the PL/J genetic background. No significant differences were noted between groups for the frequency, severity and duration of EAE, and the frequency of relapses. Our results indicate that IL-4, despite its well-documented regulatory role in EAE, is not necessary for the spontaneous remission of disease or for the prevention of relapses. Therefore, in the absence of IL-4, overlapping or compensatory immunoregulatory mechanisms can restrict an inflammatory response within the central nervous system.

Abstract

T-cells specific for a region of human myelin basic protein, amino acids 87-99 (hMBP87-99), have been implicated in the development of multiple sclerosis (MS) a demyelinating disease of the central nervous system. Administration of soluble altered peptide ligand (APL), made by substituting native residues with alanine at either positions 91(91K > A or A91) or 97 (97R > A or A97) in the hMBP87-99 peptide, blocked the development of chronic relapsing experimental autoimmune encephalomyelitis (R-EAE), in the SJL mouse. The non-encephalitogenic APL A91, appears to induce cytokine shifts from Th1 to Th2 in the target T-cells, whereas the encephalitogenic superagonist APL A97 causes deletion of the MBP87-99 responsive cells. Thus, single amino acid changes at different positions in the same peptide epitope can lead to APL capable of controlling auto-immune disease by different mechanisms.

Abstract

We evaluated myoblast implantation in 10 boys with Duchenne muscular dystrophy (DMD) and absent dystrophin (age 5-10 years) who were implanted with 100 million myoblasts in the anterior tibial muscle of one leg and placebo in the other. Cyclosporine (5 mg/kg/day) was administered for 7 months. Pre- and postimplantation (after 1 and 6 months) muscle biopsies were analyzed. Force generation (tetanic tension and maximum voluntary contraction) was measured monthly in a double-blind design. There was increased force generation in both legs of all boys, probably due to cyclosporine. Using the polymerase chain reaction, evidence of myoblast survival and dystrophin mRNA expression was obtained in 3 patients after 1 month and in 1 patient after 6 months. These studies suggest a salutary effect of cyclosporine upon muscular force generation in Duchenne muscular dystrophy; however, myoblast implantation was not effective in replacing clinically significant amounts of dystrophin in DMD muscle.

Abstract

Aminoguanidine (AG), a selective inhibitor of inducible nitric oxide synthase, prevented the clinical development of experimental autoimmune encephalomyelitis (EAE) with a reduction in inflammation and demyelination. Administration of AG reduced the expression of nitrosotyrosine in inflammatory lesions in the central nervous system. Cytokine expression, determined by semiquantitative PCR, revealed increased expression of IFN-gamma, IL-10, and TGF-beta, which was associated with protection from EAE, and reduced TNF-alpha, associated with the development of EAE. Furthermore, AG blocked the secretion of nitric oxide, TNF-alpha, and PGE2 in astrocyte cultures. AG did not influence the proliferation response of T cells to a pathogenic epitope of myelin basic protein. Down-regulation of nitric oxide by AG has widespread consequences for cytokine production in central nervous system inflammation and prevents EAE.

Abstract

T cells are considered to be of prime importance in immune regulation of both B and T cell functions. The targets of recognition in T-T cell interactions are not clear. Most recent experimental work has focused on the idiotypic regulatory interactions mediated by TCR peptides. There is experimental evidence that regulatory cells exist that do not recognize the TCR. This type of regulation is selectively induced by activated T cells. Therefore, we designed this study to examine the possible role of cytokine receptors as targets of immune regulation. We tested two peptides of IL-2R alpha-chain, 2 of IL-2R beta-chain, and one of TNFR (p60). All peptides were found to be immunogenic at inducing T cell proliferation and four induced Abs in Lewis rats. We generated T cell lines to these five peptides, and tested them both in vitro and in vivo. We found that the T cells exhibited a proliferative response when cultured with activated, irradiated stimulator cells that were augmented upon addition of the cytokine receptor peptide. The cytokine profile of the lines was characterized as well as the Vbeta gene composition. One of the lines significantly protected against active encephalomyelitis. These results point at cytokine receptors as possible targets of immune regulation and T-T cell interactions.

Abstract

We have examined the functional consequences induced by interaction of DR2a-restricted myelin basic protein (MBP) (87-99)-specific T cell clones (TCC) with altered peptide ligands (APL) derived from MBP peptide (87-99). The immunodominant MBP peptide (87-99) has been implicated as a candidate antigen in multiple sclerosis (MS) by several lines of evidence. In the present study, we have defined the T cell receptor (TCR) contact residues for DR2a-restricted, (87-99)-specific T helper type 1 T cells to design APL suitable to modify the functions of such T cells potentially relevant for the pathogenesis of MS. We show that neutral (L-alanine substitutions) or conservative exchanges of the primary and secondary TCR contact residues lead to various alterations of T cell function, ranging from differences in interleukin-2 receptor up-regulation to anergy induction and TCR antagonism. The potential usefulness of APL as an immunomodulating therapy for DR2+ MS patients is discussed.

Abstract

Multiple sclerosis (MS) is a demyelinating disease during which an autoimmune reaction is directed against oligodendrocytes. Alterations of normal myelin structure or oligodendrocyte metabolism may be primary events that influence the susceptibility to MS. Once triggered, the immune system attacks and destroys myelin and the myelin forming cell. Evidence is presented that the oligodendrocyte responds to the attack by immune cells and their secreted products through modulation of its metabolism and gene expression. Cytokines, immunoglobulins, and complement complexes may elicit a survival response in the oligodendrocytes, involving the induction of heat shock proteins and other protective molecules. The possibility of manipulating these complex glial cell functions and controlling their pathologic interactions with immune cells will illuminate how myelin damage can be contained and how the injured tissue can be repaired.

Abstract

A variable region gene of the T-cell receptor, V beta 8.2, is rearranged, and its product is expressed on pathogenic T cells that induce experimental autoimmune encephalomyelitis (EAE) in H-2u mice after immunization with myelin basic protein (MBP). Vaccination of these mice with naked DNA encoding V beta 8.2 protected mice from EAE. Analysis of T cells reacting to the pathogenic portion of the MBP molecule indicated that in the vaccinated mice there was a reduction in the Th1 cytokines interleukin-2 (IL-2) and interferon-gama. In parallel, there was an elevation in the production of IL-4, a Th2 cytokine associated with suppression of disease. A novel feature of DNA immunization for autoimmune disease, reversal of the autoimmune response from Th1 to Th2, may make this approach attractive for treatment of Th1-mediated diseases like multiple sclerosis, juvenile diabetes and rheumatoid arthritis.

Abstract

We have examined the level of surface expression and functional properties of leukocyte function associated antigen-1, very late antigen-4, and CD45 isoforms on a panel of human CD4+ T-cell clones representative of TH0, TH1, and TH2 cells. There were no qualitative differences in the expression of these antigens among the three types of CD4+ T-cell clones. However, CD45RB was the only CD45 isoform that provided a costimulatory signal in a solid-phase antibody-induced cellular proliferation assay. Additionally, the antigen-induced proliferative response of T-cell clones was inhibited by soluble anti-CD45RO and anti-CD45RB antibodies. Our results suggest that CD45 isoforms differentially provide costimulatory signals to T cells. However, the ability of each CD45 isoform to provide a costimulatory signal does not differ among the TH0, TH1, or TH2 T-cell populations.

Abstract

The development of restricted cytokine profiles by subsets of CD4+ T cells is a pivotal point in the regulation of immune responses. T cells producing Th1 cytokines (IL-2 and interferon-gamma) induce cell-mediated immunity, whereas T cells producing Th2 cytokines (IL-4, IL-5, and IL-10) play a prominent role in the induction of humoral immunity. We examined a group of patients with multiple sclerosis, a disease caused by excess production of Th1 cytokines in myelin-reactive T cells, and control patients with noninflammatory neuroconvulsive disorders, for the presence of allergic disease, which is caused by excess production of Th2 cytokines in allergen-specific T cells. The patients with multiple sclerosis had significantly fewer allergic symptoms, a lower number of positive allergen-specific IgE test results, and lower composite allergy indexes than control subjects. These results demonstrate that the prevalence of IgE-mediated allergic disease is decreased in a group of patients with multiple sclerosis and support the hypothesis that genetic factors that promote susceptibility to Th1-mediated inflammatory disease in human beings protect against the development of Th2-mediated disease.

Abstract

Experimental autoimmune encephalomyelitis (EAE) can be adoptively transferred by T cells that are specific for autoantigens of the central nervous system. A variety of autoantigens and their derived peptides have been shown to be excellent stimulators for encephalitogenic T-cell lines and clones. This article describes protocols for the establishment and characterization of autoreactive T-cell lines and clones and for the study of EAE induced by these cells. The rationale for using transferred EAE models is discussed, together with advantages and disadvantages of using in vitro cultured T cells compared with Freund's adjuvant-based immunization for the induction of EAE.

A few autoreactive cells in an autoimmune infiltrate control a vast population of nonspecific cells: A tale of smart bombs and the infantryPROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICASteinman, L.1996; 93 (6): 2253-2256

Abstract

Inflammatory infiltrates in tissue-specific autoimmune disease comprise a collection of T cells with specificity for an antigen in the target organ. These specific cells recruit a population of nonspecific T cells and macrophages. The rare tissue-specific T cells in the infiltrate have the capacity to regulate both the influx and the efflux of cells from the tissue. Administration of an altered peptide ligand for the specific T cell which triggers autoimmunity can lead to the regression of the entire inflammatory ensemble in a few hours. Interleukin 4 is a critical cytokine involved in the regression of the inflammatory infiltrate.

Abstract

Following induction of experimental encephalomyelitis with a T-cell clone, L10C1, that is specific for the myelin basic protein epitope p87-99, the inflammatory infiltrate in the central nervous system contains a diverse collection of T cells with heterogeneous receptors. We show here that when clone L10C1 is tolerized in vivo with an analogue of p87-99, established paralysis is reversed, inflammatory infiltrates regress, and the heterogeneous T-cell infiltrate disappears from the brain, with only the T-cell clones that incited disease remaining in the original lesions. We found that antibody raised against interleukin-4 reversed the tolerance induced by the altered peptide ligand. Treatment with this altered peptide ligand selectively silences pathogenic T cells and actively signals for the efflux of other T cells recruited to the site of disease as a result of the production of interleukin-4 and the reduction of tumour-necrosis factor-alpha in the lesion.

Abstract

Experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis, is an autoimmune disorder seen in mice and rats following immunization with myelin basic protein (MBP) or MBP-derived peptides. IFN-gamma, a cytokine produced by a variety of cells, is involved in many inflammatory and immune regulatory events. Contradictory results concerning exacerbations and the disease course were seen comparing injections of IFN-gamma in humans suffering from multiple sclerosis to studies using anti-IFN-gamma Abs in mice with EAE. To study the role of IFN-gamma and IFN-gamma-producing cells in EAE, we crossed IFN-gamma knockout mice (H-2b) (unable to produce IFN-gamma due to the disruption of the IFN-gamma gene) with an EAE-susceptible mouse strain, B10.PL (H-2u). EAE was seen in IFN-gamma knockout mice, heterozygotic (IFN-gamma +/-) mice, as well as wild-type littermates following immunization with MBP. Histologic analyses of the central nervous system of IFN-gamma knockout mice with EAE revealed massive infiltrates composed of lymphocytes, macrophages, and granulocytes. We conclude that the presence of IFN-gamma is not crucial to the induction or the clinical course of EAE.

Abstract

The purpose of this study was to characterize the phenotype and clonality of the T cell population in patients who experience acute rejection (AR) following bone marrow transplantation (BMT) from a partially mismatched related donor (PMRD). Phenotypic analysis was performed using flow cytometry, assignment of donor/host lineage by cytogenetics or HLA-specific flow cytometry, and analysis of the T cell receptor (TCR) by reverse-transcriptase polymerase chain reaction (RT-PCR). We have previously reported the initial appearance in the blood of AR patients of host CD8+brightCD3low T cells that progressively express increasing amounts of CD3+ cells. We now report that this cell population can differentiate into either a cytotoxic T cell phenotype (CD3+CD8+HLA-DR+CD57-) usually associated with AR of grafts from matched unrelated donors or a suppressor T cell phenotype (CD3+CD8+CD57+HLA-DR-) usually associated with AR of grafts from matched sibling donors. Analysis of the TCR V beta subsets from two patients revealed sorted host CD3+CD8+ cells (purity 90-95%) from the first patient to express V beta 18 almost exclusively. In a second patient with late rejection (55 days post-BMT), the CD3+CD8+ cells were predominantly restricted to V beta 1, 5.1, 7, 9, and 18. Although CD3+CD8+ T cells are known to be associated with AR, cytotoxic and suppressor lineages in AR from the same type of BMT and clonal distribution of T cells in AR have not been reported. Preliminary results suggest that V beta expression in AR of PMRD grafts is restricted and host T cell phenotype may vary. Further studies will investigate whether specific mismatches correlate with specific V beta usage and/or host T cell phenotype.

FINE SPECIFICITY OF THE ANTIBODY-RESPONSE TO MYELIN BASIC-PROTEIN IN THE CENTRAL-NERVOUS-SYSTEM IN MULTIPLE-SCLEROSIS - THE MINIMAL B-CELL EPITOPE AND A MODEL OF ITS FEATURESPROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICAWarren, K. G., Catz, I., Steinman, L.1995; 92 (24): 11061-11065

Abstract

We previously demonstrated the local production of the pleiotropic cytokine interleukin-6 (IL-6) in the central nervous system (CNS) in experimental autoimmune encephalomyelitis (EAE), an animal model for the human disease multiple sclerosis.To assess the role of IL-6 in autoimmune CNS inflammation, we administered neutralizing antibodies to IL-6 in the EAE model. Their effect was examined at the clinical and histopathological level. Levels of administered antibody and IL-6 bioactivity were followed in serum and cerebrospinal fluid (CSF).Systemically administered antibodies penetrated into the fluid CSF in animals in which EAE was induced. Administration of anti-IL-6 reduced the development of actively induced as well as adoptively transferred EAE and was associated with increased levels of IL-6 activity in the CSF and to a lesser extent in the serum. Anti-IL-6 was still effective when given 1 day before the onset of disease signs in adoptively transferred EAE. The disease-reducing effect of anti-IL-6 was also reflected at the pathological level by the absence of inflammatory infiltrates in the CNS.Our study indicates that IL-6 plays an important role in autoimmune CNS inflammation. However, due to the complex nature of the in vivo interactions of administered antibodies, the disease-reducing effect of the anti-IL-6 antibodies could be caused by neutralization of IL-6 activity or by enhancement of IL-6 activity via induction of higher IL-6 levels in the CNS.

Abstract

Analysis of pathogen-reactive T cell clones (CD3+4+8-TCR alpha beta +), isolated from the synovial fluid of 2 HLA-B27-positive patients with Yersinia enterocolitica-triggered reactive arthritis, has provided important information about the cellular immune response to this disease-inciting pathogen. This study demonstrates that the proteins secreted by Y. enterocolitica, including a protein with tyrosine phosphatase activity (YopH), are potent immunogens stimulating CD4+ cells within the inflamed joint. The pathogen-reactive T cell clones preferentially utilized a limited set of T cell receptor variable region gene segments. A purified Yersinia superantigen triggered a proliferative response in most of the antigen-reactive T cell clones tested. These results suggest that the activity of this pathogen's superantigen influences the cellular immune response to its antigens.

Abstract

Experimental autoimmune encephalomyelitis (EAE) in Lewis rats and some strains of mice is typically a monophasic disease, and recovered animals are resistant to reinduction of disease. We demonstrate that SJL mice remain susceptible to disease after recovery, and suffer a second episode of disease when reinjected with spinal cord homogenate in complete Freund's adjuvant. Reinduced disease occurs earlier after injection than the initial disease (mean onset 7.3 days compared with 14.5 days), and has comparable severity and incidence. The susceptibility to reinduced disease is present for at least 20 weeks after the initial injection. If the initial episode of EAE is elicited using a synthetic peptide of proteolipid protein, then reinjection of the same peptide causes reinduced disease. PL/J mice and PL/J x SJL F1 mice are also susceptible to reinduced disease which occurs with an accelerated onset and higher incidence than the initial disease. We conclude that SJL and PL/J mice have a defect in immunoregulation which causes them to be susceptible to recurrent episodes of autoimmune disease.

Abstract

Evidence is emerging that the major T- and B-cell response in multiple sclerosis (MS) is directed to a region of myelin basic protein (MBP) between residues 84 and 103. In rodent models of MS, immunization to this component of MBP evokes experimental autoimmune encephalomyelitis (EAE). T cells found in EAE lesions show similarities in the VJ and VDJ regions of their alpha and beta chains with T cells in MS lesions, and with T cells that are specific for MBPp84-103 isolated from patients with MS. If this region of MBP is critical in the pathogenesis of MS, then therapy aimed at controlling the immune response to this immunodominant region of MBP may be beneficial in treating MS.

Abstract

We have used two approaches to isolate TCR sequences that are unique to patients with multiple sclerosis. One strategy was to sequence TCR gene rearrangements directly from MS lesions. The second strategy utilized T-cell clones with a selectable mutation that are found only in MS patients. The selection of T-cell clones with mutations in the hypoxanthine guanine phosphoribosyltransferase (hprt) gene was used to isolate T-cells reactive to myelin basic protein (MBP) in patients with multiple sclerosis (MS). These T-cell clones are activated in vivo, and are not found in healthy individuals. The third complementarity determining regions (CDR3) of the T-cell receptor (TCR) alpha and beta chains are the putative contact sites for peptide fragments of MBP bound in the groove of the HLA molecule. The TCR V gene usage and CDR3s of these MBP-reactive hprt- T-cell clones are homologous to TCRs from other T-cells relevant to MS, including T-cells causing experimental allergic encephalomyelitis (EAE) and T-cells found in brain lesions and in the cerebrospinal fluid (CSF) of MS patients. In vivo activated MBP-reactive T-cells in MS patients may be critical in the pathogenesis of MS.

Abstract

CSF lymphocytes from patients with Coccidioides immitis meningitis exhibited a significant antigen-specific response to in vitro stimulation with C. immitis antigens. In some patients, lesser responses to control antigens (Candida and PPD) were also detected. Antigen-specific responses by CSF lymphocytes were seen early in the course of this disease as well as several years after patients had entered remission. When compared to CSF cells, the response of autologous peripheral blood mononuclear cells was similar but of a much smaller magnitude and at times undetectable. Fluorescence activated cell sorting revealed an increased percentage of CD3+ (T-cells), CD4+ (helper/inducer) and CD3+/HLA-DR+ (activated T-cell) cells in the CSF of C. immitis meningitis patients compared to their blood. Most of the antigen-specific proliferative response resided in the CD4+ lymphocyte subset. CSF T-cell proliferation assays may have a role in the diagnosis of C. immitis meningitis.

A PREDOMINANT ROLE OF INTEGRIN ALPHA(4) IN THE SPONTANEOUS DEVELOPMENT OF AUTOIMMUNE DIABETES IN NONOBESE DIABETIC MICEPROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICAYang, X. D., Michie, S. A., Tisch, R., Karin, N., Steinman, L., McDevitt, H. O.1994; 91 (26): 12604-12608

Abstract

To elucidate the role of cell adhesion molecules in the pathogenesis of insulin-dependent diabetes mellitus and to determine the predominant lymphocytic homing pathway(s) involved in the selective lymphocytic infiltration of pancreatic islets (insulitis), nonobese diabetic mice were treated with monoclonal antibodies specific for the L-selectin and integrin alpha 4 lymphocyte adhesion molecules. Treatment of neonatal mice with either anti-L-selectin or anti-integrin alpha 4 monoclonal antibodies for the first 4 weeks of life led to a significant and long-term protection against spontaneous occurrence of insulitis and diabetes. The same treatment failed to inhibit lymphocytic infiltration of the salivary glands (sialadenitis). This tissue-specific inhibition of inflammation may be attributed to differences between the pancreas and salivary gland in their expression of endothelial ligands for L-selectin (peripheral vascular addressin) and for integrin alpha 4 (mucosal addressin cell adhesion molecule 1 and vascular cell adhesion molecule 1). Mucosal addressin cell adhesion molecule 1 is highly expressed by vessels within the inflamed islets but was not detected in the salivary glands. In contrast, peripheral vascular addressin- and vascular cell adhesion molecule 1-expressing vessels can be found in almost every area of inflammation within the salivary glands but are seen in only 40-50% of inflamed islets. Anti-L-selectin and anti-integrin alpha 4 treatment had no demonstrable effect on anti-beta-cell autoimmunity or on the immune responses to foreign antigens. Therapeutic treatment with anti-L-selectin after the onset of insulitis from 10 to 14 weeks of age delayed the onset but failed to prevent spontaneous insulin-dependent diabetes mellitus, whereas anti-integrin alpha 4 treatment resulted in a significant and long-lasting suppression of the disease. These data strongly suggest that integrin alpha 4 plays a prominent role in the spontaneous development of insulitis and diabetes in nonobese diabetic mice.

Abstract

An immunodominant epitope of myelin basic protein (MBP), VHFFKNIVTPRTP (p87-99), is a major target of T cells in lesions of multiple sclerosis (MS) and in experimental allergic encephalomyelitis (EAE). T cells found in EAE lesions bear the same amino acids in the third complementary determining region of the T cell receptor (TCR) as those found in MS lesions. We analyzed the trimolecular interactions between MBP p87-99, class II major histocompatibility complex (MHC), and TCR, and designed soluble inhibitors for therapy. F, N, I, and V at positions 90, 92, 93, and 94 interact with MHC, whereas K, T, and P at positions 91, 95, and 96 interact with TCR. The peptides, p87-99[95T > A] and p87-99[96P > A] could compete more effectively with p87-99 for binding to MHC and could antagonize the in vitro response to T cells to p87-99 more effectively than p87-99[91K > A]. However, only p87-99[91K > A] prevented and reversed EAE, indicating that the extent of MHC or TCR competition does not predict success in treating EAE. To elucidate the mechanism of inhibition of EAE, draining lymph node cells from rats immunized with the native peptide alone or together with each of the three TCR antagonists were challenged in vitro with p87-99. Administration of p87-99[91K > A], but not p87-99 [95T > A] or p87-99[96P > A], reduced the production of tumor necrosis factor (TNF)- alpha and interferon (IFN) gamma. IFN-gamma and TNF-alpha are two cytokines that are critical in the pathogenesis of EAE and MS.

Abstract

Gelatinases, belonging to the matrix metalloproteases, contribute to tissue destruction in inflammatory demyelinating disorders of the central nervous system such as multiple sclerosis. We used experimental autoimmune encephalomyelitis (EAE) as an animal model to evaluate the effect of a hydroxamate matrix metalloprotease inhibitor (GM 6001) on inflammatory demyelination. A single dose of the inhibitor, given intraperitoneally, provided sufficient levels in the cerebrospinal fluid of animals with EAE to induce at least a partial inhibition of the gelatinase activity in the cerebrospinal fluid. When administered daily either from the time of disease induction or from the onset of clinical signs, GM 6001 suppressed the development or reversed clinical EAE in a dose-dependent way, respectively. Animals returned to the same clinical course as the nontreated group after cessation of treatment. Animals treated from the onset of clinical signs had normal permeability of the blood-brain barrier, compared with the enhanced permeability in nontreated animals. These results indicate that matrix metalloprotease inhibition can reverse ongoing EAE. This effect appears to be mediated mainly through restoration of the damaged blood-brain barrier in the inflammatory phase of the disease, since, the degree of demyelination and inflammation did not differ between the treatment groups.

Abstract

Selective homing of autoreactive lymphocytes to the pancreatic islets of Langerhans is essential for triggering the cascade of molecular and cellular interactions which culminate in the specific destruction of the insulin-producing beta-cells. Based upon the sequential multistep model of lymphocyte adhesion to the endothelium, we investigated the possibility of preventing the progression of insulin-dependent diabetes mellitus (IDDM) by selectively blocking L-selectin and alpha 4-integrin homing receptors, which function at different stages of the adhesion process. Treatment of NOD mice with mAb specific for L-selectin or alpha 4-integrin resulted in a significant inhibition of lymphocytic infiltration (insulitis). Both spontaneous development and acute transfer of IDDM were completely prevented by administration of anti-alpha 4-integrin antibody and partially inhibited by anti-L-selectin antibody. The protective effect was of long duration. Interestingly, the autoimmune T cell responses to a panel of beta cell autoantigens and the lymphocytic infiltration of salivary glands (sialadenitis) appeared unaffected by anti-L-selectin or anti-alpha 4-integrin treatment. These data suggest that prevention of lymphocyte homing to the pancreatic islets may provide a selective target for prevention/treatment of IDDM in patients.

Abstract

Mononuclear cells infiltrate degenerating muscles of Duchenne muscular dystrophy (DMD) patients. Using a quantitative PCR, we first characterized the T cells infiltrating muscle biopsies from six DMD patients. High levels of TCR V beta 2 transcripts were observed in DMD muscle tissue. TCR V beta 2 transcripts from seven DMD patients and five controls were sequenced, and the VDJ junctional region analyzed in 166 clones. One specific amino acid motif, RVSG, was found in the third complementary determining region (CDR3) of TCR V beta 2 chains in samples from five DMD patients, but not in controls. A specific immune reaction at the site of tissue degeneration may play an important role in the pathogenesis of DMD.

Abstract

Characterization of T cells responding to autoantigens is central to understanding autoimmune disease. We have used somatic mutation at the hypoxanthine guanine phosphoribosyltransferase (HPRT) gene as an index of T-cell amplification in vivo. With this strategy we previously showed that myelin basic protein-reactive T cells can be isolated only from the HPRT mutant T-cell population cultured from the peripheral blood of multiple sclerosis patients and not from normal individuals. In this study, 165 HPRT mutant and 104 wild-type clones were examined for their reactivity to myelin basic protein and overlapping peptides of myelin basic protein. Five HPRT mutant clones that recognized myelin basic protein and myelin basic protein peptides along with three clones that responded to myelin basic protein peptide alone were isolated. All but one of the eight clones recognized peptides derived from the carboxy terminus of myelin basic protein (p84-168). Sequence analysis showed heterogeneous expression of T-cell receptor V alpha and V beta genes and CDR3s. These studies showed that in vivo amplified autoimmune T cells from patients with long-standing disease use diverse T-cell receptor elements in the recognition of C-terminal myelin basic protein peptides.

Abstract

We treated 21 multiple sclerosis patients with two to four doses of cM-T412, a chimeric monoclonal antibody against the CD4 antigen found on helper/inducer T lymphocytes. The mean number (+/- standard error) of circulating CD4 lymphocytes decreased from 888 (+/- 81) cells/mm3 at baseline to 246 (+/- 18) after treatment. At 1 year after the last treatment, the CD4 count had recovered to only 335 (+/- 32). The antibody had no effect on CD8 lymphocytes, B lymphocytes, or other leukocytes. Side effects were minimal. Despite the prolonged depletion of CD4 lymphocytes, no opportunistic infections occurred. Only 1 patient had a possible allergic reaction. Most patients were clinically stable, but a few progressed. We conclude that repeated treatment with cM-T412 is effective in reducing the number of circulating CD4 lymphocytes and has no limiting side effects.

Abstract

The selection of T cell clones with mutations in the hypoxanthine guanine phosphoribosyltransferase (hprt) gene has been used to isolate T cells reactive to myelin basic protein (MBP) in patients with multiple sclerosis (MS). These T cell clones are activated in vivo, and are not found in healthy individuals. The third complementarity determining regions (CDR3) of the T cell receptor (TCR) alpha and beta chains are the putative contact sites for peptide fragments of MBP bound in the groove of the HLA molecule. The TCR V gene usage and CDR3s of these MBP-reactive hprt-T cell clones are homologous to TCRs from other T cells relevant to MS, including T cells causing experimental allergic encephalomyelitis (EAE) and T cells found in brain lesions and in the cerebrospinal fluid (CSF) of MS patients. In vivo activated MBP-reactive T cells in MS patients may be critical in the pathogenesis of MS.

Abstract

A hippocampal 38 kd autoantigen recognized by an autoantibody from the serum of a patient with paraneoplastic limbic encephalitis (PLE) and small cell lung carcinoma (SCLC) was isolated by screening a human hippocampal cDNA library. The 1,991-nucleotide ple21 clone was obtained and the deduced 350-residue protein encoded by the ple21 cDNA clone was found to be highly homologous to the neuron-specific RNA recognition motifs (RRMs)-containing proteins. The homologies were confined to the RRMs and the RRM connecting region. The presence of RRM in the antigenic protein may be important in the pathogenesis of SCLC-associated paraneoplastic neurologic syndrome.

Abstract

We conducted an open trial of cM-T412, a chimeric monoclonal anti-CD4 antibody, in 29 patients with MS. This antibody caused a prompt and long-lasting depletion of circulating CD4 (helper/inducer) lymphocytes. The mean (+/- SE) CD4 count for the group decreased from 870 (+/- 66) cells/mm3 at baseline to 76 (+/- 11) 3 hours after treatment, and then increased to 425 (+/- 38) at 1 month after treatment and 475 (+/- 39) at 6 months after treatment. Numbers of CD8 (cytotoxic/suppressor) lymphocytes, B lymphocytes, granulocytes, and monocytes changed transiently but showed no significant long-term effects. The most common side effects were headache, nausea, myalgia, fever, and tachycardia occurring in the first few hours after treatment. No serious or unexpected infections or other significant adverse effects occurred. Kurtzke EDSS scores remained stable, and MRI scans showed less contrast enhancement 1 week after treatment. We conclude that treatment of MS patients with cM-T412 chimeric anti-CD4 antibody is well tolerated at the doses tested and produces a long-lasting, selective depletion of CD4 lymphocytes.

Abstract

The precise mechanisms of failure of immunological tolerance to self proteins are not known. Major histocompatibility complex (MHC) susceptibility alleles, the target peptides, and T cells with anti-self reactivity must be present to cause autoimmune diseases. Experimental autoimmune encephalomyelitis (EAE) is a murine model of a human autoimmune disease, multiple sclerosis. In EAE, residues 1-11 of myelin basic protein (MBP) are the dominant disease-inducing determinants in PL/J and (PL/J x SJL/J)F1 mice. Here we report that a six-residue peptide (five of them native) of MBP can induce EAE. Using peptide analogues of the MBP-(1-11) peptide, we demonstrate that only four native MBP residues are required to stimulate MBP-specific T cells. Therefore, this study demonstrates lower minimum structural requirements for effective antigen presentation by MHC class II molecules. Many viral and bacterial proteins share short runs of amino acid similarity with host self proteins, a phenomenon known as molecular mimicry. Since a six-residue peptide can sensitize MBP-specific T cells to cause EAE, these results define a minimum sequence identity for molecular mimicry in autoimmunity.

Abstract

To evaluate the role of candidate genes in the susceptibility to multiple sclerosis (MS) and describe the role of T-cell receptor (TCR) gene rearrangements in the MS brain lesion in identifying a major target of the immune response in this disease.MEDLINE, bibliography review of published data, and unpublished studies.Published studies using novel molecular approaches to analyze the role of the major histocompatibility complex (MHC) and TCR gene complexes, as well as other candidate genes, in susceptibility to MS. We analyze epigenetic events involving TCR genes in individuals with MS and describe recent clinical trials in which immunotherapy has been attempted.Consistent with a polygenic model for disease predisposition, MHC and TCR gene associations with MS are relatively weak. Despite intensive research, no other putative "MS genes" have been firmly established. The analysis of TCR rearrangements in the brain lesion has helped to identify a major target of the immune response in MS.Understanding the genetic basis for autoimmune demyelination will offer new possibilities for the treatment of this illness.

INHIBITION OF INSULITIS AND PREVENTION OF DIABETES IN NONOBESE DIABETIC MICE BY BLOCKING L-SELECTIN AND VERY LATE ANTIGEN-4 ADHESION RECEPTORSPROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICAYang, X. D., Karin, N., Tisch, R., Steinman, L., McDevitt, H. O.1993; 90 (22): 10494-10498

Abstract

Leukocyte adhesion to the endothelial venules in the pancreatic islets is thought to be one of the initial steps in the development of insulin-dependent diabetes mellitus. It has been suggested that leukocyte adhesion to endothelium is a sequential multistep process involving various different homing receptors. We report here that blocking different homing receptors--namely, L-selectin and very late antigen 4 (VLA-4)--which function during different stages of the adhesion process, by specific monoclonal antibodies inhibits insulitis and prevents diabetes in mice. Moreover, leukocyte attachment to the inflamed vessels within pancreatic sections could be inhibited by anti-L-selectin and anti-VLA-4 antibodies. Interestingly, anti-L-selectin or anti-VLA-4 antibody did not appear to influence the autoimmune response to a panel of pancreatic beta-cell autoantigens. These data suggest that L-selectin and VLA-4 receptors are involved in mediating leukocyte homing to the islets and that intervention of these two adhesion pathways may provide a novel approach for treatment of autoimmune diseases such as insulin-dependent diabetes mellitus.

Abstract

We used competitive polymerase chain reaction to quantify messenger RNA for the lymphocyte antigens CD4 and CD8, the adhesion molecules ICAM-1 and VCAM-1, and the MHC class II I-A molecule in the spinal cords of SJL/J mice at multiple times during the development and resolution of experimental allergic encephalomyelitis (EAE). CD4 and CD8 were not quantifiable at baseline, became detectable at 5 days after immunization, and increased steadily to a peak during clinical disease. I-A increased after CD4 and CD8, but before onset of disease. ICAM-1 and VCAM-1 did not increase until after onset of clinical disease. CD4, CD8, and I-A remained elevated long after recovery from disease. These results suggest that infiltration of CD4 and CD8 cells into the spinal cord and subsequent upregulation of I-A mRNA play an important role in the development of EAE, but reversal of these processes is not necessary for recovery. Upregulation of ICAM-1 and VCAM-1 mRNA does not appear to be important for development of disease.

Abstract

The role of infection in the pathogenesis of clinical relapses that occur in most autoimmune diseases, including multiple sclerosis, remains to be established. Experimental autoimmune encephalomyelitis (EAE) serves as a model for multiple sclerosis, with episodes of relapsing paralysis. In certain strains of mice, T-lymphocytes expressing the V beta 8 T-cell receptor (TCR) engage the amino-terminal epitope Ac1-11 of myelin basic protein, leading to EAE. The bacterial superantigen staphylococcal enterotoxin B (SEB) activates V beta 8-expressing T cells. Here we show that after immunization with Ac1-11, or after transfer of encephalitogenic T-cell lines or clones reactive to Ac1-11, SEB induces exacerbation or relapses of paralytic disease in mice that are in clinical remission following an initial episode of paralysis, and triggers paralysis in mice with subclinical disease. Tumour necrosis factor has a critical role in the mechanism underlying SEB-induced exacerbation of disease, because anti-tumour necrosis factor antibody given in vivo delays the onset of paralysis triggered by SEB. On reactivation of autoaggressive cells through their T-cell receptor, superantigens may induce clinical relapses of autoimmune disease.

Abstract

In this study we analyzed the usage frequencies of the TCR V-gene segments by alpha beta+ T cells present in synovial fluid of 17 patients with chronic arthritis, including rheumatoid arthritis. The results of this study, obtained from semiquantitative PCR analyses, showed that in all patients most of the TCR V alpha- and V beta-gene segments could be detected both in fresh PBMCs and in fresh SFMCs. The relative frequencies of use of these V-region genes were variable between the different patients. Although there was some skewing of increased usage frequencies of particular TCR V alpha and V beta genes among SFMC-derived TCRs when compared with PBMCs, we could not correlate such increased TCR V-gene usage with the inflammation in the joints as a disease-specific marker.

Abstract

The identification of activated T cells in the brains of patients with multiple sclerosis (MS) suggests that these cells are critical in the pathogenesis of this disease. Recently we have used the PCR method to analyse rearrangements of V alpha and V beta genes of the T cell receptor (TCR) in samples of MS and control brains. The results of these studies showed that TCR V gene usage in MS brains may be restricted and in particular that V beta genes may be preferentially rearranged in certain HLA haplotypes associated with susceptibility to MS. In view of the recent evidence that T lymphocytes bearing the gamma delta chains may have autoreactive potential, we have assessed whether or not such TCR-bearing lymphocytes were also present in chronic MS lesions. TCR V gamma and V delta were analysed by the PCR method using a panel of V gamma and V delta primers paired with C gamma or C delta primers in 12 MS brains, as well as in brain samples of ten normal post-mortem cases and three neurological controls. TCR V gamma-C gamma and V delta-C delta rearrangements were confirmed using Southern blotting and hybridisation of the PCR products with specific C gamma and C delta probes. Only one to four rearranged TCR V gamma and V delta transcripts were detected in each of the 23 brain samples obtained from 12 MS patients, with the majority of gamma delta T cells expressing the V gamma 2 and V delta 2 chains. In marked contrast, V gamma and V delta transcripts could only be found in one of the ten non-neurological control brains analysed. To assess the clonality of V gamma 2 and V delta 2 T cell receptor chains in the brain samples of MS patients, we have sequenced the junctional regions of the TCR V gamma-N-J gamma-C gamma and V delta-N-D delta-N-J delta-C delta segments amplified from brain tissues, CSF and spleens of two MS patients and from the spleen of two control subjects. The sequence analysis obtained so far shows no compelling evidence of an MS specific expansion of one or more clones expressing particular types of gamma delta T cell receptors. In contrast, a clonal expansion of a different population of TCR gamma delta-bearing T cells was found in the spleen of both an MS patient and one of the control individuals.(ABSTRACT TRUNCATED AT 400 WORDS)

Abstract

To study in vivo activated cytolytic T cells, CD8+ T cells clones were isolated from a melanoma patient (HLA A2, A11) treated with active specific immunotherapy for 5 years. CD8+ T lymphocytes, purified by fluorescence-activated cell sorting, were cloned directly from the peripheral blood without antigen-presenting cells in the presence of irradiated autologous melanoma cells and recombinant interleukin-2 (IL-2) and IL-4. These conditions were inhibitory to de novo in vitro immunization. Of the 28 cytolytic CD8+ T cell clones, 21 lysed the autologous melanoma cell line (M7) but not the autologous lymphoblastoid cell line (LCL-7) nor the two melanoma cell line, M1 (HLA A28) and M2 (HLA A28, A31), used to immunize the patient. The remaining 7 clones were also melanoma-specific, although their reactivities were broader, lysing several melanoma cell lines but not HLA-matched lymphoblastoid cells. Eight clones from the first group, ostensibly self-MHC-restricted, were expanded for further analysis. All expressed cluster determinants characteristic of mature, activated T cells, but not those of thymocytes, naive T cells, B cells or natural killer (NK) cells. They also expressed CD13, a myeloid marker. Of the 8 clones, 3 expressed both CD4 and CD8, but dual expression was not correlated with specificity of lysis. Two CD8+ and 2 CD4+ CD8+ clones were specific for the autologous melanoma cells, the other 4 were also reactive against other HLA-A2-positive melanomas. Cytotoxicity for both singly and doubly positive clones was restricted by HLA class I but not class II antigens. Analysis of the RNA expression of the T cell receptor (TCR) V alpha and V beta gene segments revealed heterogeneous usage by the A2-restricted clones and, perhaps, also by the broadly melanoma-specific clones. Apparent TCR-restricted usage was noted for the self-MHC-restricted clones; 2 of the 4 expressed the V alpha 17/V beta 7 dimer. Since the T cell clones were derived from separate precursors of circulating cytotoxic T lymphocytes (CTL), the V alpha 17/V beta 7 TCR was well represented in the peripheral blood lymphocytes of this patient. In summary, we show that melanoma cells presented their own antigens to stimulate the proliferation of melanoma-reactive CD8+ CTL. CTL with a range of melanoma specificities and different TCR alpha beta dimers were encountered in this patient, perhaps as a result of hyperimmunization.(ABSTRACT TRUNCATED AT 400 WORDS)

Abstract

Improved molecular methods allow identification of the specific autoaggressive T cells involved in autoimmune inflammations. In this study of interphotoreceptor retinoid-binding protein-induced uveitis, TCR V beta usage was studied using RNA-polymerase chain reaction amplification of transcripts derived directly from ocular tissues and from T cell lines obtained from the spleen. Specific V beta 5' primers from the major murine TCR V beta families were coupled with a common 3' primer from the V beta C region. Amplification of rearranged TCR V beta-D beta-J beta-C beta sequences was confirmed by Southern blot analysis. In ocular tissue from sensitized mice, TCR V beta expression was limited mainly to one to three V beta families, with predominant expression of V beta 2, V beta 12, and V beta 15. In most animals there was similar, albeit limited, TCR gene usage in both the recognition of autoantigen in uveitogenic T cell lines and at the site of inflammation in the eye. Identification of a limited TCR V beta repertoire in Ag-reactive T cell lines correlated with TCR usage at the target site of autoimmune expression. The gene products of the restricted TCR V beta rearrangements found in lesions and in the cell lines may serve as the target for selective immunotherapy.

Abstract

Forty-three CD3+4+8- TCR alpha beta+ Borrelia burgdorferi-reactive T cell clones isolated from the peripheral blood of a single patient with clinically active chronic Lyme arthritis were characterized. The spirochetal Ag recognized by 16 of these T cell clones was determined by reactivity with a panel of recombinant spirochetal Ag, which included the OspA, OspB, flagellin, Hsp60 and Hsp70 proteins. All three T cell clones reactive with heat shock proteins recognized a non-cross-reactive epitope unique to the spirochetal Ag. Analysis of the TCR V regions revealed preferential usage of V beta 5.1; 5 of 15 T cell clones that recognized an unidentified spirochetal Ag utilized this V beta gene segment. Most of the T cell clones recognized a given spirochetal Ag exclusively within the context of one HLA class II allele. However, two T cell clones, which recognized an unidentified Ag in the spirochetal lysate within the context of different HLA class II alleles, were both TCR V beta 5.1+, although each displayed a distinct alpha-chain. Moreover, in vitro incubation of this patient's PBMC with B. burgdorferi Ag resulted in a specific increase in the percentage of T cells expressing TCR V beta 5.1. These results indicate that B. burgdorferi has a V beta-selective factor influencing the cellular immune response in a patient with clinically active Lyme disease.

Abstract

The repertoire of TCR V beta genes transcribed and expressed within the central nervous system was determined in mice with experimental allergic encephalomyelitis. Disease was induced in (PL/J x SJL/)F1 mice by immunizing with myelin basic protein-acetylated peptide 1-11, and mice were sacrificed at intervals from day 3 postimmunization to 3 wk after recovery from disease. Transcription of V beta genes was determined by reverse transcriptase polymerase chain reaction on RNA extracted from spinal cord, and expression of the V beta gene products was detected by immunohistochemistry with mAb specific for various V beta proteins. Multiple V beta genes were found to be transcribed and expressed in the central nervous system starting 7 days after immunization, and continuing up to 3 wk after clinical recovery. Preferential utilization of a single TCR V beta gene was not detected in the central nervous system at any time in the course of disease.

Abstract

The diversity of Ag-specific receptors on T cells homing to an inflammatory infiltrate in the central nervous system has been analyzed. Experimental autoimmune encephalomyelitis, a T cell-mediated inflammatory disease of the central nervous system, was induced in Lewis rats with a CD4+, CD8- T cell line specific for peptide 68-86 of myelin basic protein. Within the line a wide array of TCR V beta genes was transcribed including the V beta 8, V beta 10, V beta 15, V beta 16, and V beta 19 families. Accumulation of T cells at the site of inflammation was determined by using RNA-polymerase chain reaction amplification of rearranged TCR V beta transcripts derived from brain. By 8 to 10 h after i.p. infusion of the pathogenic T cell line, TCR V beta transcripts, including mainly V beta families that were predominantly rearranged by the line, could be identified in brains. Restricted TCR V gene transcripts with predominance of the V beta 8 family were identified in brain 48 h after injection, before onset of disease. Paralysis was apparent by 4 to 5 days after injection. At this time diverse V beta gene transcripts were detected in brain, reaching a maximum by day 9, when paralyzed rats have recovered. By day 14 a second stage of limited heterogeneity in the T cell infiltrate could be identified with predominant expression of V beta 8, V beta 9, V beta 10, and V beta 19. Interestingly, three out of these four V beta families were predominantly expressed within the encephalitogenic line. Thus, T cell migration to brain in experimental autoimmune encephalomyelitis is characterized by a rapid penetration of T cells followed by a selective trapping of T cells before the clinical manifestations of disease. When clinical disease was present the T cell infiltrate was diverse, whereas in the post-acute phase of disease the T cells in the central nervous system had limited heterogeneity with selective accumulation of T cells transcribing the same V regions that were detected in the line that incited disease.

Abstract

Superantigens have the ability to stimulate a subset of T cells based upon their expressed TCR beta-chain. It has been demonstrated that the administration of staphylococcal enterotoxin B (SEB) in mice leads to unresponsiveness in V beta 8+ T cells in vivo which are the same T cells that could be stimulated in vitro by this enterotoxin. We present here data on the effect of SEB administration in DBA/2 and (PL/J x SJL)F1 mice on their T cell response to two different T cell determinants, the responses against which are dominated by the use of V beta 8+ T cells. Treatment of mice with SEB not only diminished their primary T cell proliferative response to these determinants, but also was able to effectively reduce the memory T cell response. SEB treatment, however, showed only a modest effect in preventing Ac 1-11-induced experimental autoimmune encephalomyelitis in H-2u mice.

Abstract

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system in which a restricted cellular immune response has been observed. In order to establish whether such T cell responses are likely to be antigen-specific particularly with regard to myelin basic protein (MBP), we analysed T-cell receptor (TCR) gene rearrangements directly from MS brain plaques, using the polymerase chain reaction on reverse transcribed messenger RNA, and compared these with TCR of previously described MBP-specific T cell clones from MS and the rat model experimental allergic encephalomyelitis. Rearranged V beta 5.2 genes were detected in the brains of all patients who were HLA DRB1*1501, DQA1*0102, DQB1*0602, DPB1*0401. The V beta 5.2-D beta-J beta sequences in these MS brain plaques revealed five motifs. One of the common motifs was identical to that described for the VDJ region of a V beta 5.2 T-cell clone. This clone was from an MS patient who was HLA DRB1*1501, DQB1*0602, DPB1*0401, and it was cytotoxic towards targets containing the MBP peptide 89-106 (ref. 1). The deduced amino-acid sequence of this VDJ rearrangement, Leu-Arg-Gly, has also been described in rat T cells cloned from experimental allergic encephalomyelitis lesions, which are specific for MBP peptide 87-99 (ref. 2). VDJ sequences with specificity for this MBP epitope constitute a large fraction (40%) of the TCR V beta 5.2 N(D)N rearrangements in MS lesions. The capacity of rat T cells with these VDJ sequences to cause experimental allergic encephalomyelitis and the prevalence of such sequences in demyelinated human lesions indicate that T cells with this rearranged TCR may be critical in MS.

Abstract

A 45-year-old man with a longstanding diagnosis of myasthenia gravis presented with four episodes of transverse myelitis in 5 years. Each episode improved after treatment with steroids. Laboratory studies revealed no evidence of multiple sclerosis or a structural spinal lesion. He had antinuclear and anti-DNA antibodies and the HLA-A1, B8, DR3 haplotype known to be associated with certain autoimmune diseases. We propose an autoimmune cause for the recurrent episodes of myelitis.

Abstract

The minimum structural requirements for peptide interactions with major histocompatibility complex (MHC) class II molecules and with T cell receptors (TCRs) were examined. In this report we show that substituting alanines at all but five amino acids in the myelin basic protein (MBP) peptide Ac1-11 does not alter its ability to bind A alpha uA beta u (MHC class II molecules), to stimulate specific T cells and, surprisingly, to induce experimental autoimmune encephalomyelitis (EAE) in (PL/J x SJL/J)F1 mice. Most other amino acid side chains in the Ac1-11 peptide are essentially irrelevant for T cell stimulation and for disease induction. Further analysis revealed that binding to A alpha uA beta u occurred with a peptide that consists mainly of alanines and only three of the original residues of Ac1-11. Moreover, when used as a coimmunogen with MBP Ac1-11, this peptide inhibited EAE. The finding that a specific in vivo response can be generated by a peptide containing only five native residues provides evidence that disease-inducing TCRs recognize only a very short sequence of the MHC-bound peptide.

Abstract

Expression of the lymphokine genes in human astroglial cell lineage was studied. Primers for 9 different human lymphokines, from IL-1 alpha to IL-8, were used to analyze RNA transcripts in 5 cultured human astrocytoma, one neuroblastoma cell line and 4 fresh brain specimens by polymerase chain reaction (PCR). mRNA transcripts of neither IL-1 nor IL-3, the biological activities of which were observed in rat primary cultured astrocytes, could be detected within these cell lines. Two out of 5 unstimulated astrocytomas, U138 and U373, expressed IL-6 genes. IL-8 gene was detected within U87, U138, U251, U373 glioma cells. After stimulation with IL-1 beta, all astrocytoma and one neuroblastoma cell line expressed IL-6 and IL-8 genes. In addition to the cultured cells, we examined IL-6 and IL-8 gene expression within human malignant astrocytoma specimens. The result shows that three out of four glioma specimens expressed IL-6 and IL-8 genes. From these results, it is suspected that astroglial cell-derived IL-6 or IL-8 may participate in local immune reactions accompanying infection, degeneration and malignancies in the central nervous system.

Abstract

The profile of lymphokines secreted by 14 T cell clones and 24 T cell lines reactive with Yersinia Ag isolated from the synovial fluid cells of two HLA-B27+ patients with Yersinia-triggered reactive arthritis was characterized. In response to Ag-specific or -nonspecific stimulation, all of the Yersinia-reactive T cell clones and lines had a pattern of lymphokine secretion resembling that of murine (Th1) cells. A total of 50% of T cell lines and clones randomly isolated from a reactive arthritis patient, without prior in vitro stimulation with Yersinia Ag, also exhibited a Th1-like profile of cytokine secretion upon nonspecific activation. This indicates that the selective expansion of this subset of T cells had already occurred in vivo. The possibility that the predominance of Th1-like T cells was an artefact generated by the T cell cloning procedure was excluded; 50% of the randomly isolated T cell clones and lines produced IL-4, IL-5, or both cytokines upon nonspecific activation. These results indicate that Yersinia Ag selectively activate a Th1-like subset of T cells in patients with Yersinia-triggered reactive arthritis. Accumulation of such cells in the synovial tissue of patients with reactive arthritis may play a key role in the pathogenesis of this disease.

Abstract

Experimental autoimmune encephalomyelitis (EAE) is an inflammatory neurologic disease initiated by myelin basic protein-reactive CD4+ T cells, which are restricted by a particular MHC class II molecule. Recent studies have utilized inhibitor peptides that bind to restricting MHC class II molecules in order to inhibit EAE, presumably by means of competing with encephalitogenic epitopes. However, these studies leave open the possibility of alternative explanations, such as Ag-specific nonresponsiveness and immunodominance. In order to demonstrate that competition for MHC binding alone can inhibit EAE, the inhibitor peptide should ideally be structurally unrelated and nonimmunogenic yet physically associate with the MHC class II molecule. In this study, we show that the OVA-323-339 peptide, which is unrelated to the disease-inducing peptide, binds to A alpha uA beta u. However, although OVA-323-339 is extremely immunogenic in A alpha dA beta d-expressing BALB/c mice, it is nonimmunogenic in (PL/J x SJL)F1 and PL/J mice expressing A alpha uA beta u. When administered as a coimmunogen with Ac1-11, OVA-323-339 inhibited induction of EAE in (PL/J x SJL)F1 mice. Myelin basic protein-89-101, which does not bind A alpha uA beta u, had no effect on the disease process. This study provides evidence that MHC class II binding alone can modulate the induction of EAE. The use of a nonimmunogenic non-self peptide to modulate an autoimmune disease minimizes the potential complications of immunodominance or alternative regulatory mechanisms associated with immunogenic peptide therapies and further confirms the MHC-blocking model of immunosuppression.

Abstract

Applications of PCR have revolutionized the field of immunogenetics particularly in studies of human leukocyte antigen class II polymorphism and more recently in the analysis of T cell receptor usage. The diversity of the variable region of the T cell receptor, however, has made it difficult to amplify the complete repertoire of T cell receptor transcripts. We have chosen to address this problem through the design of oligonucleotide primers specific for each of the known V alpha- and V beta-region T cell receptor families in order to characterize the T cell receptor repertoire. Using nonradioactive probes labeled with horse radish peroxidase, the system presented here allows for the rapid elucidation of the T cell receptor repertoire expressed in cells or tissue samples, such as those derived from autoimmune lesions. The identification of the T cell receptor repertoire involved in a pathogenic process can have therapeutic implications given the success of reversing experimental autoimmune disorders by directing specific forms of immunotherapy against V region gene products.

Abstract

Gene delivery by transplantation of normal myoblasts has been proposed as a treatment of the primary defect, lack of the muscle protein dystrophin, that causes Duchenne muscular dystrophy (DMD), a lethal human muscle degenerative disorder. To test this possibility, we transplanted normal myoblasts from a father or an unaffected sibling into the muscle of eight boys with DMD, and assessed their production of dystrophin. Three patients with deletions in the dystrophin gene expressed normal dystrophin transcripts in muscle biopsy specimens taken from the transplant site one month after myoblast injection. Using the polymerase chain reaction we established that the dystrophin in these biopsies derived from donor myoblast DNA. These results show that transplanted myoblasts persist and produce dystrophin in muscle fibres of DMD patients.

Abstract

Applications of the polymerase chain reaction have revolutionized the field of immunogenetics, particularly in studies of human leukocyte antigen class II polymorphism, and more recently in the analysis of T-cell receptor usage. However, the enormous diversity and variability of the T-cell receptor complex have made the amplification of the complete repertoire difficult. Several methods have been devised to address this problem. Each system is described with recent examples of its use and an assessment of its advantages and disadvantages. The use of quantitative polymerase chain reaction in T-cell receptor analysis is also discussed. The elucidation of the T-cell repertoire involved in a pathogenic process can have therapeutic implications, given the success of reversing experimental autoimmune disorders by directing specific forms of immunotherapy against V region gene products.

Abstract

The interaction of the immunodominant pertussis toxin peptide containing residues 30-42 (p30-42) with soluble DR1 molecules and the T-cell receptor (TCR) of 12 DR1-restricted human T-cell clones has been analyzed. Peptide analogues of p30-42 containing single alanine substitutions were used in DR1-binding and T-cell proliferation assays to identify the major histocompatibility complex and TCR contact residues. Each T-cell clone was found to recognize p30-42 with a different fine specificity. However, a common core comprising amino acids 33-39 was found to be important for stimulation of all T-cell clones. Within this core two residues, Leu33 and Leu36, interact with the DR1 molecule, whereas Asp34, His35, Thr37, and Arg39 are important for TCR recognition in most of the clones. Computer modeling of the structure of p30-42 showed that an alpha-helical conformation is compatible with the experimental data. The analysis of TCR rearrangement revealed that the peptide was recognized by T-cell clones expressing different variable region alpha (V alpha) and variable region beta (V beta) chains, although a preferential use of V alpha 8-V beta 13 and V alpha 11-V beta 18 combinations was found in clones from the same donor. Understanding the details of the interaction of antigenic peptides with the major histocompatibility complex and TCR molecules should provide the theoretical basis to design T-cell epitopes and obtain more immunogenic vaccines.

Abstract

Experimental autoimmune encephalomyelitis (EAE) is an inflammatory condition of the central nervous system with similarities to multiple sclerosis. In both diseases, circulating leukocytes penetrate the blood-brain barrier and damage myelin, resulting in impaired nerve conduction and paralysis. We sought to identify the adhesion receptors that mediate the attachment of circulating leukocytes to inflamed brain endothelium in EAE, because this interaction is the first step in leukocyte entry into the central nervous system. Using an in vitro adhesion assay on tissue sections, we found that lymphocytes and monocytes bound selectively to inflamed EAE brain vessels. Binding was inhibited by antibodies against the integrin molecule alpha 4 beta 1, but not by antibodies against numerous other adhesion receptors. When tested in vivo, anti-alpha 4 integrin effectively prevented the accumulation of leukocytes in the central nervous system and the development of EAE. Thus, therapies designed to interfere with alpha 4 beta 1 integrin may be useful in treating inflammatory diseases of the central nervous system, such as multiple sclerosis.

Abstract

Anti-I-A antibodies, administered in vivo at the time of S-antigen injection, suppress development of experimental autoimmune uveitis (EAU) in Lewis rats. While the effects of anti-I-A are profound, the exact mechanism for this suppression is unknown. We attempted adoptive transfer of this form of suppression by injecting lymphocytes from anti-I-A-treated animals into syngeneic recipients which were later injected with S-antigen. Histologically, globes of 75% of the anti-I-A-treated animals showed no inflammation while 25% of these animals developed mild uveitis. In the group of animals which were injected with S-antigen and also received spleen cells from anti-I-A-treated rats, only 1 showed mild uveitis while the remaining 7 had no inflammation. The animals undergoing adoptive transfer of spleen cells and which were primed with an irrelevant antigen, readily developed uveitis. Suppression of S-antigen-induced EAU was abrogated by pretreatment of donor animals with cyclophosphamide. In vitro studies revealed that spleen cells of S-antigen-primed, anti-I-A-treated donors specifically suppressed lymphocyte responses to S-antigen. These in vivo and in vitro results suggest that generation of antigen-specific suppressor cells play a role in the anti-I-A immunotherapy of EAU.

Abstract

With the aim of investigating the distribution of T cells expressing different T-cell receptors (TCR) in the inflamed synovial tissue of rheumatoid arthritis patients, we have used the polymerase chain reaction to amplify TCR V alpha and V beta transcripts from synovial biopsies obtained by arthroscopy from patients with arthritis of variable duration. From each of nine patients a single biopsy was taken. Southern hybridization analysis of amplified products revealed extensive heterogeneity of TCR V beta in most patients. On the other hand, restriction in V alpha gene expression was seen in several patients. A highly restricted V alpha repertoire was observed in all cases with arthritis of short duration. In addition, two of three samples of short duration yielded a more limited number of V beta transcripts than the others. No conformity was, however, seen in usage of individual V alpha and V beta transcripts among the investigated patients. The present data thus demonstrate variability in synovial TCR expression between rheumatoid arthritis patients, but they also indicate a development towards greater diversity with increasing disease duration, implicating the necessity for careful choice of cases, preferentially selecting for early stages of disease, when further analysing rheumatoid synovial T cells for TCR usage as well as for antigen specificity.

Abstract

Expression of granulocyte (G) and granulocyte-macrophage (GM) colony stimulating factor (CSF) genes in human cells of astroglial lineage was studied. Primers for CSFs were used to analyze RNA transcripts in 5 cultured human astrocytoma cell lines and 8 fresh brain specimens by polymerase chain reaction. Constitutive expression of mRNA transcripts of GM-CSF could be detected in all astrocytoma and one neuroblastoma cell lines, and two out of 5 unstimulated astrocytomas, U87MG and U138 MG, expressed G-CSF genes. After stimulation with interleukin (IL)-1 beta + tumor necrosis factor (TNF)-alpha, all cell lines expressed G-CSF. In addition to the cultured cells, we examined gene expression within human malignant astrocytoma, peritumoral brain and autopsied normal brains. The results show that some of the tumor and its surrounding reactive lesions express G- and GM-CSF genes but normal brains do not. The concentration of G- and GM-CSF in supernatants of cultured cells was assessed at the protein level by ELISA. A low level of GM-CSF activity was constitutively present in all astrocytomas. G-CSF was detected in unstimulated U87MG and U138MG and other cell lines could synthesize G-CSF after the stimulation of IL-1 beta and TNF-alpha at the level of mRNA. Furthermore, the concentration of CSFs increased markedly upon stimulation with IL-1 beta and/or TNF-alpha in both a time- and dose-dependent fashion. From these results, it is suspected that astroglial cell-derived CSFs may participate in local immune reactions accompanying infection, degeneration and malignancies in the brain.

Abstract

The cellular and molecular requirements for the autoimmune disease EAE are being defined in increasing detail through intense scrutiny of critical autoantigenic peptides, class II MHC molecules, and alpha beta TCRs involved in the disease process. This study has led to novel immunotherapeutic approaches, many of which are based on the administration of synthetic peptides. Since short peptides are understood to be the minimal antigenic units bound by MHC molecules for recognition by T cells, they are attractive experimental tools for finely modulating specific immune responses. It is clear that a large number of defined peptides can dramatically influence the course of EAE. Table IV lists a number of potential mechanisms which may mediate disease prevention. Increasing evidence supports the idea that prevention of autoimmune disease can result from MHC-blockade by peptides which competitively bind to class II molecules. However, for some peptides such as the perplexing partial agonist Ac1-11[4A], the mechanism by which these precisely defined units act is not yet fully understood. Numerous hurdles hinder immediate clinical application of peptide-based immunotherapy. Nevertheless, the knowledge gained by probing experimental autoimmunity with defined peptides promises to inspire original and practical approaches to treating human autoimmune disease.

Abstract

Expression of lymphokine genes in the human astroglial cell lineage was studied. Primers for 9 different human lymphokines, from IL-1 alpha to IL-8, were used to analyze RNA transcripts in 5 cultured human astrocytoma cell lines and fresh brain specimens by PCR. mRNA transcripts for IL-8 were detected in all neuroglial cells. In addition to the cultured cells, we examined IL-8 gene expression within human malignant astrocytoma, peritumoral brain and autopsied normal brains. The result shows that tumor and cells of the surrounding reactive lesion express IL-8 genes, but it is not expressed in normal brains. Next, the concentration of IL-8 in supernatants of cultured cells was measured quantitatively by a solid phase ELISA assay. IL-8 activity was produced constitutively in all astrocytomas and increased markedly upon stimulation with IL-1 beta or TNF alpha, in both a time- and dose-dependent fashion. From these results, it is suspected that astroglial cell-derived IL-8 may take part in neutrophil-mediated inflammation which accompanies infection, degeneration and malignancy in the brain.

Abstract

Expression of the Cytokine genes in human astroglial cell lineage was studied. Primers for 5 different human cytokine, TNF-alpha, -beta, IFN-gamma, G-CSF and GM-CSF, were used to analyze messenger RNA transcripts in 5 cultured human astrocytoma, one neuroblastoma cell lines and fresh brain specimens by polymerase chain reaction (PCR). Three out of 5 unstimulated astrocytomas, U138, U251, U373 MG and IMR32 neuroblastoma cells expressed TNF-alpha genes. After stimulation with IL-1 beta (1000 U/ml) all these cell lines expressed TNF-alpha genes. TNF-beta genes could not be detected in these cell lines even in the presence of any cytokine stimuli. We were able to detect expression of IFN-gamma genes within 2 astrocytoma cell lines (U87MG and A172), which interestingly did not show TNF-alpha activity. Constitutive expression of mRNA transcripts of GM -CSF could be detected in all astrocytoma and two out of 5 unstimulated astrocytomas, U87MG and U138MG, expressed G-CSF genes. After stimulation with IL-1 beta, all cell lines expressed G-CSF. In addition, we also examined gene expression of these cytokines within 4 human malignant astrocytoma specimens, 2 peritumoral brain and 2 autopsied normal brains. The results show that tumor and surrounding lesions express TNF-alpha (4 of 6), TNF-beta (1/6), IFN-gamma (4/6), G-CSF (3/6) and GM-CSF (5/6) but not normal brains. One tumor specimen also expresses TNF-beta as well as TNF-alpha genes (case 2). From these results, it is suspected that astroglial cell-derived cytokines may participate in local immune reactions accompanying glioma in the brain.

A SINGLE AMINO-ACID CHANGE IN A MYELIN BASIC-PROTEIN PEPTIDE CONFERS THE CAPACITY TO PREVENT RATHER THAN INDUCE EXPERIMENTAL AUTOIMMUNE ENCEPHALOMYELITISPROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICASmilek, D. E., Wraith, D. C., Hodgkinson, S., Dwivedy, S., Steinman, L., McDevitt, H. O.1991; 88 (21): 9633-9637

Abstract

Experimental autoimmune encephalomyelitis (EAE) is an experimental demyelinating disease of rodents. In (PL/J x SJL) F1 mice, it is induced by immunization with the myelin basic protein peptide Ac1-11. Ac1-11 [4A], a myelin basic protein peptide analog with a single amino acid substitution, (i) binds to class II major histocompatibility complex molecules and stimulates encephalitogenic T cells in vitro better than Ac1-11, (ii) is nonimmunogenic and nonencephalitogenic in vivo in (PL/J x SJL)F1 mice, (iii) prevents EAE when administered before or at the time of immunization with Ac1-11, and (iv) prevents EAE when administered later, near the time of disease onset. Initial studies suggest that Ac1-11 [4A] does not prevent EAE by competitive inhibition or by activation of regulatory cells. Thus, substitution of a single amino acid in a myelin basic protein peptide confers the capacity to prevent rather than induce EAE, even after peptide-specific encephalitogenic T cells have been activated.

Abstract

Expression of T-cell-receptor (TCR) V alpha and V beta genes in tumor-infiltrating lymphocytes (TILs) of 29 patients, 15 melanomas and 14 malignant glial tumors (glioma and medulloblastoma), was investigated. The identification and propagation of T cells with anti-tumor reactivity is crucial to the understanding of the human immune response to tumors, which may possibly be useful in the successful implementation of adoptive immunotherapy against cancer. Despite clinical evidence that a more favorable prognosis is associated with the degree of lymphocyte infiltration within a tumor, the actual role of TIL remains uncertain. In order to address this question, we examined the diversity of the RNA transcripts of TCR genes in TILs within 29 specimens obtained at surgery. Using the polymerase-chain-reaction (PCR) method and primers for 18 different human TCR V alpha and 21 V beta families to analyze TCR V-(D)-J-C gene rearrangements, we detected a limited expression of TCR variable-region V alpha genes of TILs. TCR V beta gene rearrangements were more diverse than those for V alpha. In addition to restricted usage of TCR V alpha genes, preferential expression of V alpha 7 genes was found in 20 out of 29 cases (69%). Predominant usage of V alpha 7 genes was more remarkable in melanoma TILs (14/15) than in glial tumor TILs (6/14). These findings were also confirmed by Southern blot analysis with oligonucleotide probes for the constant (C) region of TCR alpha and beta chains. We suspect that some specific T-cell populations may be directed to antigenic determinants in melanoma cells.

Abstract

Expression of T-cell receptor (TCR) gene rearrangements in tumor-infiltrating lymphocytes (TILs) within primary and metastatic melanoma specimens was studied. In order to analyze TCR gene transcription in TILs within these tissues, we analyzed reverse transcribed complementary DNA from mRNA directly from tissues using the polymerase chain reaction. The polymerase chain reaction-amplified products were confirmed by dot or Southern blot hybridization with C alpha or C beta oligoprobes. First, we investigated the diversity of TCR V alpha and V beta gene usage in human malignant melanoma patients with multiple metastasis. We found in one patient, bearing multiple skin lesions, that the patterns of TCR V alpha and V beta repertoires in different sites of the skin (leg and chest wall) were almost the same. However, in another patient with skin and brain melanomas, different TCR repertoires were presented. Next, we examined the usage of murine TCR V beta genes in TILs within the primary and metastatic sites (liver, lung, and brain) of C57BL/6 mice bearing B16-F10 murine melanoma. The population of TILs in each primary and metastatic site expressed from one to four TCR V beta genes. In each metastatic site, the profile of TCR V beta gene expression was different. A different TCR V beta usage in TILs distributed within metastases of various organs may reflect differences in tumor antigenicity at these sites or may be due to differential homing patterns to these tumors.

Abstract

The pace of research on the pathogenesis and treatment of multiple sclerosis, the principal human demyelinating disease of the central nervous system, has intensified in the past 3 years, due in part, to the application of advances in molecular and cellular immunology. Many lessons that have been learned in an animal model of central nervous system demyelinating disease, experimental allergic encephalomyelitis, also apply to multiple sclerosis and certain successful approaches for the treatment of this disease are now being attempted in humans.

Abstract

Some investigators have proposed myoblast transfer as a potential therapy for the treatment of Duchenne muscular dystrophy. Little is known about the immunobiology of myoblast transplantation. Transplantation rejection is mediated to a large extent by CD8+ T cells, which recognize alloantigens encoded by class I HLA genes, and by CD4+ T cells, which recognize alloantigens encoded by class II HLA genes. Gamma interferon (IFN-gamma) is a potent inducer of HLA class II molecules as well as beta 2-microglobulin, which is co-expressed with HLA class I. IFN-gamma may be a critical cytokine involved in graft rejection. We purified human myoblasts by flow cytometry and incubated them in vitro for varying time periods with recombinant human IFN-gamma. The inducibility of HLA-DR and -DP molecules raises a note of caution concerning possible rejection phenomenon which might occur following myoblast transplantation.

Abstract

To study antitumor immunity in patients with choroidal melanoma, T cells were generated from the peripheral blood of choroidal melanoma patients by mixed lymphocyte/tumor cell culture (MLTC). Because autologous tumors are generally unavailable, an allogeneic choroidal melanoma cell line, OCM-1, was used as the specific stimulus. Lymphocyte cultures from 27 patients were characterized by cell-surface phenotypes, patterns of reactivity towards cells of the melanocytic origin and T-cell-receptor gene usage. Antimelanoma reactivity was found in cell-sorter-purified CD4+ and CD8+ T cell subsets. To analyze this reactivity, sorter-purified CD4+ and CD8+ cells from a MLTC were cloned by limiting dilution in the presence of exogenous interleukin-2 and interleukin-4 as well as irradiated OCM-1. Under these conditions, CD4+ T cells did not proliferate, perhaps because of the absence of antigen-presenting cells. However, CD8+ grew vigorously and 29 cytolytic CD8+ T cell clones were isolated. On the basis of their pattern of lysis of OCM-1, a skin melanoma cell line M-7 and its autologous lymphoblastoid cell line LCL-7, the clones were categorized into three groups. Group 1, representing 52% of the clones, lysed all three target cells, and are alloreactive. However, since OCM-1 and M-7 did not share class I antigens, these clones recognized cross-reactive epitope(s) of the histocompatibility locus antigen (HLA) molecule. Group 2, constituting 28% of the clones, lysed both the ocular and skin melanoma cell lines but not LCL-7, and were apparently melanoma-specific. Unlike classical HLA-restricted cytolytic T lymphocytes, these T cells might mediate the lysis of melanoma cells via other ligands or a more degenerate type of HLA restriction. For the latter, the HLA-A2 and -A28 alleles would have to act interchangeably as the restriction element for shared melanoma-associated antigen(s). Group 3, representing only 10% of the T cell clones, was cytotoxic only to OCM-1, but not to M-7 or LCL-7. These clones may recognize antigens unique to ocular melanoma cells. Our data suggest that choroidal melanoma patients can recognize melanoma-associated antigens common to both ocular and cutaneous melanoma cells, and presumbly their autologous tumor. Thus, choroidal melanoma, like its skin counterpart, may be responsive to immunotherapeutic regimens such as active specific or adoptive cellular immunotherapy.

Abstract

Experimental allergic encephalomyelitis (EAE) is a T cell mediated model of demyelinating disease that develops as a result of an autoimmune response to the myelin structural antigen, myelin basic protein (MBP). Much information has accumulated on the nature of trimolecular interactions which lead to the activation of self-reactive T lymphocytes in this disorder. Many parallels exist in the etiopathogenesis of EAE and multiple sclerosis (MS). Based upon these similarities selective immunotherapy that targets either class II molecules of the major histocompatibility complex or T cell receptor variable region genes will be described for EAE with consideration given to application of these principles in MS.

Abstract

Oligonucleotide probes were used to investigate the role of DQ beta molecules in susceptibility to multiple sclerosis. Although shared amino acid and nucleotide sequences in DQ beta 1 have been suggested to be critical in disease development, we find that the distribution of sequences corresponding to residues 71-77 is not greater in patients versus controls.

Abstract

Chimeric (murine/human) anti-CD4 monoclonal antibody was infused into seven patients with mycosis fungoides. Successive patients received doses of 10, 20, 40, and 80 mg of antibody twice a week for 3 consecutive weeks. All patients had some clinical improvement, but responses were of relatively short duration. Serum levels of chimeric antibody varied as a function of dose. At the 80-mg dose level, antibody was readily observed in biopsied skin lesions. Although there was coating by antibody of most CD4 positive cells in the blood, there was no significant depletion of CD4 positive cells. Low-level antibody responses against the mouse Ig variable region and human Ig allotypic constant region determinants were observed in several patients, but none were of clinical significance. All but two patients made primary antibody and T-cell proliferative responses to a simultaneously administered foreign protein test antigen. However, there was marked suppression of the mixed lymphocyte reaction. We conclude that at the dose levels studied, a chimeric anti-CD4 monoclonal antibody (1) had some clinical efficacy against mycosis fungoides; (2) was well tolerated; (3) had a low level of immunogenicity; (4) had immediate immunosuppressive effects; and (5) did not induce tolerance to a co-injected antigen.

Abstract

We isolated a complementary DNA clone encoding a 52-kd protein recognized by an anti-neuronal cell antibody in serum from a patient with paraneoplastic cerebellar degeneration associated with uterine carcinoma. The recombinant protein expressed in prokaryotic cells was specifically recognized by the anti-neuronal cell antibody from the patient, and its molecular weight was identical to that of antigenic proteins in the cerebellum. The deduced protein consisted of 450 amino acids dominated by hydrophilic residues, the calculated relative molecular mass was 51,238, and the predicted value of the isoelectric point was 4.99. This complementary DNA sequence and the deduced protein sequence have not been reported previously, and the sequences showed no homologies with the complimentary DNA or the amino acid sequences in the GenBank, EMBL, or NBRF databases, including the complementary DNA for a 34-kd cerebellar protein (CDR34) that is recognized by an anti-Purkinje cell antibody. Unexpectedly, the transcript of this gene was detected not only in the cerebellum and the brain stem but also in an extraneural tissue, the intestine.

The use of monoclonal antibodies for treatment of autoimmune disease.Journal of clinical immunologySteinman, L.1990; 10 (6): 30S-38S

Abstract

Over the past decade monoclonal antibodies have been successfully employed in a number of animal models of autoimmune disease. We have used antibodies to the class II gene products of the major histocompatibility complex, the CD4 molecule on helper T cells, and the T-cell receptor. Monoclonal anti-class II antibodies have been administered to treat paralytic disease in the animal model of multiple sclerosis--experimental allergic encephalomyelitis. These antibodies not only reverse acute paralytic disease but also decrease the number of relapses in a model of relapsing/remitting multiple sclerosis when given after the first attack. The advantage of this form of therapy is that it is haplotype specific. In other words, in a heterozygous individual it is possible to block the major histocompatibility gene associated with disease susceptibility while leaving other major histocompatibility gene products free for antigen presentation. Thus, animals given this form of immunotherapy are not significantly immunosuppressed. Antibodies to the CD4 molecule have been equally effective in treating animal models of autoimmunity. We and others have reversed ongoing paralysis in experimental autoimmune encephalomyelitis. Relapses have been diminished after the administration of anti-CD4. Antibodies to CD4 have been used successfully to treat animal models of systemic lupus erythematosus, rheumatoid arthritis and myasthenia gravis. Recent trials with anti-CD4 have been successful in the treatment of rheumatoid arthritis and cutaneous T-cell lymphoma. The latter trial employed a chimeric human/mouse antibody. Antibodies to the variable region of the T-cell receptor have been employed to treat experimental autoimmune encephalomyelitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Abstract

Human T-cell lymphotropic virus (HTLV-I) was recently reported to be etiologically associated with multiple sclerosis (MS). Genomic DNA from peripheral blood lymphocytes and brain plaques of patients with MS was analyzed for the presence of sequences homologous to the HTLV-I pol gene using the polymerase chain reaction and dot blot techniques. Comparison of DNA amplification patterns between patients with MS, and with control subjects who have other autoimmune conditions, with those in healthy control subjects and with an HTLV-I-infected cell line indicates that HTLV-I pol sequence is not present in the peripheral blood of patients with MS, and that the virus is not active in MS brain plaques.

Abstract

Expression of T cell receptor (TCR) V alpha genes in tumor-infiltrating lymphocytes (TILs) within intraocular melanoma was studied. Primers for 18 different human TCR V alpha families were used to analyze TCR V alpha-C alpha gene rearrangements in TIL in these melanomas obtained at surgery. A limited number of TCR V alpha genes were expressed and rearranged in these tumors, and TILs expressing V alpha 7 were found in seven of eight of these uveal melanomas. TCR gene usage is also restricted in experimental autoimmune disease, in T cells within organs like skin and other epithelial tissues, and in the brain of patients with multiple sclerosis (MS). The restricted usage of TCR genes in TIL may indicate that a specific antigen in these melanomas is targeted.

Abstract

In order to study the immunogenetics of myasthenia gravis (MG), we analysed the TCR and HLA-class II genes from Italian and Californian myasthenic patients. We investigated polymorphisms of the TCR using the full length cDNA probes pGA5 and the pT10 for the alpha and beta chains, respectively. The 6.3 kb and 2.0 kb polymorphic markers, revealed by the PssI enzyme and the alpha chain probe, were shown to be significantly associated with MG. Italian MG patients were HLA typed, and allele frequencies showed a significant association of DR3 and DQw2 with MG. The relative risk calculated for DR3 was 7.4. T-cell proliferative responses to peptides of the AchR alpha chain were also studied and no associations with TCR RFLP analysis or HLA-class II typing were observed.

Abstract

Reversal of autoimmune disease with monoclonal antibodies to polymorphic determinants associated with class II gene products of the major histocompatibility complex (MHC) and to T-cell receptor variable region segments has been demonstrated in animal models. Recent studies have shown that it is also possible to use mutant peptides to block recognition of self-antigen associated with MHC by T-cells that mediate autoimmune disease. These mutant peptides have been used to prevent the model autoimmune condition experimental allergic encephalomyelitis. The possibility of extending these approaches to human disease is discussed.

Abstract

Myasthenia gravis is an autoimmune disease resulting from a breakdown in T and B cell tolerance to acetylcholine receptor (AChR). Autoantibodies to AChR mediate the disease. Recent advances in experimental immunotherapy of autoimmune disease provide several possibilities for specific intervention in this well-characterized condition.

Abstract

A family of rat-mouse chimeric anti-murine CD4 antibodies was used to study the mechanisms of anti-CD4-mediated depletion and immunotherapy. The chimeric antibodies retain identical affinity and specificity as the therapeutically effective prototype antibody, rat GK1.5, but are of different mouse isotypes. GK1.5 gamma 1, GK1.5 gamma 2a, and GK1.5 gamma 2b are significantly more effective at CD4+ cell depletion than rat GK1.5 when low doses of antibody are administered. In contrast, no depletion is seen with GK1.5 gamma 3 at any dose. Depletion of CD4+ cells in vivo is not correlated with either the ability of the antibody to mediate C-dependent cytotoxicity or antibody-dependent cell-mediated cytotoxicity in vitro, implying that additional antibody-mediated cytotoxic mechanisms occur in vivo. The chimeric antibodies were used to investigate the mechanism of GK1.5-mediated immunotherapy in a prototypic model of T cell-mediated autoimmunity, experimental allergic encephalomyelitis. Mice treated with a single dose of 100 micrograms of either GK1.5, GK1.5 gamma 1, or GK1.5 gamma 2a showed significant recovery within 72 h. In contrast, mice treated with 100 micrograms of GK1.5 gamma 3 showed only marginal improvement within the first 72 h and regressed within 5 days of treatment initiation. These data suggest that anti-CD4-mediated immunotherapy of murine experimental allergic encephalomyelitis is correlated with depletion of CD4+ cells.

Abstract

Lymphokine activity in seven myelin basic protein (MBP)-specific T cell clones was examined. All of the clones recognize MBP peptide 1-9 in the context of I-Au. A strong positive correlation was found between levels of lymphotoxin (LT) and tumor necrosis factor alpha (TNF-alpha) mRNA and biological activity on L929 cells and their capacity to induce paralysis, the clinical hallmark of experimental allergic encephalomyelitis (EAE). No correlation was found between interleukin-2 or gamma interferon production and encephalitogenicity. LT and/or TNF-alpha may play a central role in the pathogenesis of EAE.

Abstract

The identification of activated T cells in the brain of individuals with multiple sclerosis (MS) indicates that these cells are critical in the pathogenesis of this disease. In an attempt to elucidate the nature of the lymphocytic infiltration, we used the polymerase chain reaction to amplify T-cell antigen receptor (TCR) V alpha sequences from transcripts derived from MS brain lesions. In each of three MS brains, only two to four rearranged TCR V alpha transcripts were detected. No V alpha transcripts could be found in control brains. Sequence analysis of transcripts encoded by the V alpha 12.1 region showed rearrangements to a limited number of J alpha region segments. These results imply that TCR V alpha gene expression in MS brain lesions is restricted.

Abstract

Peptide binding and lymph node T cell activation studies have been used to characterize T cell recognition of an encephalitogenic T cell autoantigen from myelin basic protein in mice of the H-2u haplotype. An important role for MHC class II molecules in "determinant selection" is revealed. Amino acids which determine interactions with either the restriction element of the major histocompatibility complex (MHC) or the encephalitogenic T cell receptor are defined. This information enables the design of peptides which bind MHC yet do not crossreact with the autoantigen. Two such peptides compete with the autoantigen for binding to the disease associated class II molecule and inhibit induction of experimental autoimmune encephalomyelitis in H-2u mice. Prospects for peptide mediated therapy are discussed.

GENETIC INFLUENCES ON NEUROIMMUNOLOGICAL DISEASE68TH ANNUAL SYMP OF THE ASSOC FOR RESEARCH IN NERVOUS AND MENTAL DISEASE : IMMUNOLOGIC MECHANISMS IN NEUROLOGIC AND PSYCHIATRIC DISEASESteinman, L.RAVEN PRESS.1990: 11–14

Abstract

The immunogenicity and reactogenicity of Bordetella pertussis vaccine are mediated in part by the S1 subunit of pertussis toxin (PT). To identify the immune epitopes in the S1 subunit of PT, synthetic peptides were prepared and tested for their capacity to induce antibodies in mice with different MHC genotypes. In BALB/c mice, peptides corresponding to sequences 1-17, 70-82 and 189-199 generate T cell proliferative responses, induce the production of antibodies capable of neutralization of the toxin in the Chinese hamster ovary-cell assay, and protect mice from a shock-like syndrome caused by alternate injections of BSA and PT. Protection and neutralization correlated with the ability of these peptides to elicit high anti-PT titers. Different B cell epitopes were detected in other inbred mouse strains. The antibody reactivity against synthetic peptides from two infants vaccinated with pertussis vaccine was tested. These infants had antibodies reactive to a variety of epitopes in the S1 subunit, including peptides 1-17, 70-82, 99-112, 135-145, and 189-199. Thus, it appears that there are multiple T and B cell epitopes in the S1 subunit of PT.

PREVENTION OF EXPERIMENTAL ENCEPHALOMYELITIS WITH PEPTIDES THAT BLOCK INTERACTION OF T-CELLS WITH MAJOR HISTOCOMPATIBILITY COMPLEX PROTEINSPROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICASakai, K., Zamvil, S. S., Mitchell, D. J., Hodgkinson, S., Rothbard, J. B., Steinman, L.1989; 86 (23): 9470-9474

Abstract

Two synthetic immunodominant and nonencephalitogenic peptides of myelin basic protein, N1-20 and AcN9-20, effectively compete with an encephalitogenic peptide, AcN1-11, in an in vitro T-cell response restricted by class II major histocompatibility complex products (I-Au). These mutant peptide constructs, which do not occur in nature, also compete with the self-antigen for the in vivo induction of T cells primed with the encephalitogen AcN1-11. By using these nonpathogenic competitor peptides, it is possible to prevent the development of a prototypic T-cell-mediated autoimmune disease, experimental allergic encephalomyelitis. These results suggest possibilities for the utilization of competitor peptides for therapy of T-cell-mediated autoimmune diseases linked to specific major histocompatibility complex genes.

Abstract

Peptide binding and lymph node T cell activation studies have been used to characterize T cell recognition of an encephalitogenic T cell autoantigen from myelin basic protein in (PL/J x SJL)F1 mice. Amino acids that determine interactions with either the restriction element of the major histocompatibility complex (MHC) or the encephalitogenic T cell receptor are defined. This information enables the design of peptides that bind MHC yet do not cross-react with the autoantigen. A peptide analog of the encephalitogenic epitope is shown to be "heteroclitic" for MHC binding and activation of encephalitogenic T cells in vitro. This analog is not immunogenic for encephalitogenic T cells in vivo and is shown to inhibit disease that is induced by the autoantigen itself.

Abstract

The effect of polymorphic residues on the A alpha A beta molecule on T cell recognition of the N-terminal nonapeptide of myelin basic protein (R1-9) was determined. Ak-restricted T cell clones recognizing R1-9 were isolated. The peptide-Ia specificities of these clones were determined by testing the response to 1) a panel of peptide analogs of R1-11, 2) splenic APC from mice expressing MHC molecules from serologically distinct haplotypes, and 3) L cell transfectants expressing mutant/recombinant A beta cDNA containing combinations of polymorphic nucleotide sequences from the k and u alleles. Comparisons were made between the Ak-restricted clones and a previously characterized panel of Au-restricted clones. Certain Ak-restricted clones were able to recognize MBP peptide analogs that were not recognized by any of the Au-restricted clones. The Au-restricted T cell clones did not cross-react with R1-9 presented in the context of Ak, whereas the majority of the Ak-restricted clones responded to R1-9 presented in the context of Au. This nonreciprocal cross-reactivity was also reflected in the relative responses of the two sets of T cell clones to the interchange of u- and k-derived residues in the A beta chain. Residues in regions corresponding both the alpha-helical or beta-sheet portions of the hypothetical Ia three-dimensional structure were involved. The results suggest that overall specificity of the T cell clones is the summation of numerous distinct subspecificities for different regions of the peptide-Ia ligand. These results indicate that there can be striking differences in T cell specificity for an autoantigenic epitope, even in the context of A alpha A beta molecules from very closely related haplotypes.

Abstract

The role of cAMP in lymphocyte proliferation was investigated in the response of a monoclonal T-cell population to a specific antigen and compared to the response to interleukin-2 (IL-2) and allogeneic cells. Myelin basic protein (MBP)-reactive and encephalitogenic T-cell clones were established from long-term lines derived from SJL/J (H-2s) mice. The clone 4b.14a recognizes the peptide sequence 89-101 of the MBP molecule in association with 1-As products of the major histocompatibility complex (MHC). Incubation of 4b.14a cells with syngeneic antigen-presenting cells, previously pulsed with the 89-101 synthetic peptide or with 80 U/ml of IL-2, or allogeneic H-2Ik cells, resulted in a significant increase in the accumulation of intracellular cAMP. This increase was preceded by a peak in membranal adenylate cyclase (AC) activity. Parallel time kinetics but significantly higher cAMP production and AC activity were observed when the cells were treated with pertussis toxin. At the same concentrations the toxin inhibits cellular proliferative responses, assayed by [3H]thymidine incorporation. Our results indicate the involvement of cAMP as a positive signal in the activation of the 4b.14a clone.

Abstract

GK1.5, a rat anti-mouse CD4 mAb, is effective in the treatment of several autoimmune syndromes, induces tolerance to co-administered Ag, and prolongs allograft survival. We have constructed a family of molecules with GK1.5 V regions and mouse gamma 1, gamma 2a, gamma 2b, or gamma 3 constant regions to investigate the mechanisms underlying the effectiveness of GK1.5. The rat-mouse chimeric antibodies are specific for murine CD4 and have identical binding curves as rat GK1.5 on CD4+ T cells. The chimeric GK1.5 gamma 2a, GK1.5 gamma 2b, and GK1.5 gamma 3 antibodies are more efficient than rat GK1.5 at C-mediated cytotoxicity. This is attributed to the enhanced capacity of the chimeric antibodies, compared to rat GK1.5, to lyse CD4+ cells with a low cell surface Ag density. This observation may have important implications for therapy.

Abstract

Polymorphic markers in genes encoding that alpha chain of the human T-cell receptor (TcR) have been detected by Southern blot analysis in Pss I digests. Polymorphic bands were observed at 6.3 and 2.0 kilobases (kb) with frequencies of 0.30 and 0.44, respectively, in the general population. Using the polymerase chain reaction (PCR) method, we amplified selected sequences derived from the full-length TcR alpha cDNA probe. These PCR products were used as specific probes to demonstrate that the 6.3-kb polymorphic fragment hybridizes to the variable (V)-region probe and the 2.0-kb fragment hybridizes to the constant (C)-region probe. Segregation of the polymorphic bands was analyzed in family studies. To look for associations between these markers and autoimmune diseases, we have studied the restriction fragment length polymorphism distribution of the Pss I markers in patients with multiple sclerosis, myasthenia gravis, and Graves disease. Significant differences in the frequency of the polymorphic V alpha and C alpha markers were identified between patients and healthy individuals.

T-CELL RECEPTORS IN AUTOIMMUNE-DISEASE AS TARGETS FOR IMMUNE INTERVENTION16TH INTERNATIONAL CONGRESS OF GENETICS : GENETICS AND THE UNITY OF BIOLOGYACHAORBEA, H., Steinman, L., McDevitt, H. O.NATL RESEARCH COUNCIL CANADA.1989: 656–61

Abstract

The optimal form of treatment for an autoimmune disease should be highly specific, have few side effects, and allow treatment of clinically apparent disease. One target that could fulfill these requirements is the T cell receptor. To answer the question whether treatment of autoimmune disease is possible with anti-T cell receptor antibodies, the heterogeneity of T cell receptor elements utilized in the T cell mediated autoimmune disease experimental allergic encephalomyelitis was analyzed. The limited heterogeneity of these elements allowed prevention and treatment of clinical autoimmune disease with anti-T cell receptor monoclonal antibodies. These results and their potential value for other autoimmune diseases are discussed.

Abstract

The S1 subunit of Pertussis toxin (PT) is responsible for the reactogenicity and in part the immunogenicity of Bordetella pertussis vaccine. The critical residues associated with the immunomodulatory effects of PT were located around Glu140 in the S1 subunit. In man, T cell responses to PT are directed at S1 peptides distinct from Glu140. Two such epitopes, p64-75 and p151-161, are immunogenic in a panel of individuals covering a wide range of HLA genotypes. The response to PT peptides is HLA class II restricted. The response to p64-75 is blocked by an anti-HLA-DQ mAb, while that to p151-161 is blocked by an anti-HLA-DR mAb. These findings may allow for the development of a B. pertussis vaccine free from reactogenicity.

Abstract

The peptide p89-101 (Val-His-Phe-Phe-Lys-Asn-Ile-Val-Thr-Pro-Arg-Thr-Pro) of myelin basic protein is encephalitogenic in mice expressing H-2q and H-2s antigens. Six of 13 encephalitogen-specific T-cell clones were shown to express the variable beta-chain (V beta) 17a gene product (KJ23a+), whereas seven clones were KJ23a-. Both KJ23a+ and KJ23a- subpopulations were encephalitogenic in SJL/J mice when adoptively transferred. Depletion of KJ23a+ cells in vivo with the administration of the antibody KJ23a suppresses experimental allergic encephalomyelitis induced with KJ23a+ T-cell lines. However, experimental allergic encephalomyelitis induced with either (i) encephalitogenic peptide p89-101, (ii) intact myelin basic protein, or (iii) KJ23a- T cells reactive to p89-101 cannot be prevented with monoclonal antibody KJ23a. These data indicate that in spite of the V beta 17a gene expression in a relatively large proportion of p89-101-specific T cells, such V beta gene use is not essential for the induction of experimental allergic encephalomyelitis in SJL/J mice. These results contrast with the predominance of V beta gene use (V beta 8.2) in T cells reactive to the encephalitogenic fragment (pR1-11) in PL/J mice. One reason for this lack of dominant use of a particular T-cell receptor V beta gene family in the autoimmune response to myelin basic protein in SJL/J mice stems from the observation that two encephalitogenic epitopes exist in p89-101. KJ23a- T cells are stimulated by the deleted peptide p89-100, whereas KJ23a+ T cells are not. Thus, in the response to an encephalitogenic fragment of myelin basic protein containing two nested epitopes, at least two distinct T-cell receptor V beta genes are expressed. These distinct T-cell subpopulations can each trigger experimental allergic encephalomyelitis. These findings have implications for therapy of autoimmune disease with antibodies to the T-cell receptor gene products.

Abstract

Immunization with the autoantigen myelin basic protein (MBP) causes experimental allergic encephalomyelitis (EAE). Initial investigations indicated that encephalitogenic murine determinants of MBP were located only within MBP 1-37 and MBP 89-169. Encephalitogenic T cell epitopes within these fragments have been identified. Each epitope is recognized by T cells in association with separate allelic I-A molecules. A hybrid I-E-restricted T cell clone that recognizes intact mouse (self) MBP has been examined. The epitope recognized by this clone includes MBP residues 35-47. When tested in vivo, p35-47 causes EAE. T cell recognition of p35-47 occurs only in association with I-E molecules. These results provide the first clear example that antigen-specific T cells restricted by I-E class II molecules participate in murine autoimmune disease. Furthermore, it is clear that there are multiple (at least three) discrete encephalitogenic T cell epitopes of this autoantigen, each recognized in association with separate allelic class II molecules. These results may be relevant to human autoimmune diseases whose susceptibility is associated with more than one HLA-D molecule.

Abstract

The C-terminal 89-169 amino acid fragment of myelin basic protein (MBP) causes experimental allergic encephalomyelitis (EAE) in SJL/J mice. In order to identify the encephalitogenic T cell epitope, we have examined the fine specificity of encephalitogenic SJL/J T cell clones with synthetic peptides derived from the C-terminal 89-169 amino acids of MBP. These peptides were examined for their immunogenic and encephalitogenic activity in the SJL/J mouse. The SJL/J-derived, encephalitogenic T cell clone, 4b.14a, was shown to be responsive to rat myelin basic protein synthetic peptides pR89-101 (VHFFKNIVTPRTP) as well as to intact MBP. Its response was effectively blocked by mAb 10-2.16 (anti-I-As) as was the response to intact MBP. Furthermore, pR89-101 was revealed to be highly immunogenic for the (PLSJ)F1 mouse in terms of lymphocyte proliferation, but not for the PL/J mouse, in spite of the fact that there exists a strong bias to H-2u restricted responses in the (PLSJ)F1 mouse at the T cell level. By using pR89-101, T cells of (PLSJ)F1 origin were revealed to recognize the peptide in association with the I-As molecule on (PLSJ)F1 antigen presenting cells (APC). When examined for encephalitogenicity for the SJL/J mouse, pR89-101 was found to be as encephalitogenic as intact rat MBP. These results demonstrated that MBP peptide pR89-101 is a major encephalitogenic determinant for the SJL/J mouse.

Abstract

Polymorphic markers for the human T-cell receptor (TcR) genes are described. With a TcR beta-chain probe, polymorphic allelic fragments of 5.4 and 1.8 kb were detected in KpnI digests, and fragments of 12.5 and 11.5 kb were seen in the BglII digests. Polymorphism in alpha chain genes was observed in TaqI-digested DNA samples with bands at 10.2 and 6.2-2.1 kb. Mendelian codominant inheritance for all three polymorphisms was confirmed in family studies. The gene frequencies for these alleles were determined in a sample of 70 normal unrelated Caucasian individuals, and were shown to be in Hardy-Weinberg equilibrium. There were no significant differences in the frequency of these polymorphic alpha and beta alleles between patients with multiple sclerosis and patients with myasthenia gravis as compared to a panel of control healthy individuals.

Abstract

Class II major histocompatibility (MHC) molecules have an immunoregulatory role. These cell-surface glycoproteins present fragments of protein antigens (or peptides) to thymus-derived lymphocytes (T cells). Nucleotide sequence polymorphism in the genes that encode the class II MHC products determines the specificity of the immune response and is correlated with the development of autoimmune diseases. This study identifies certain class II polymorphic amino acid residues that are strongly associated with susceptibility to insulin-dependent diabetes mellitus, rheumatoid arthritis, and pemphigus vulgaris. These findings implicate particular class II MHC isotypes in susceptibility to each disease and suggest new prophylactic and therapeutic strategies.

Abstract

The autoimmune dermatologic disease pemphigus vulgaris (PV) is associated with the HLA serotypes DR4 and DRw6. Susceptibility to PV could be conferred either by sequences shared between the DR4 and DRw6 haplotypes or by different sequences in these haplotypes. We have examined the distribution of DR and DQ beta-chain and DQ alpha-chain alleles in PV patients and in control subjects by hybridization with oligonucleotide probes and sequence analysis of in vitro amplified DNA. Ninety percent (34/38) of the DR4 haplotypes in patients contain a specific DR beta I sequence present in 36% (16 of 44) of DR4 controls (P = 0.001). This sequence is also found in DRw6 haplotypes. However, it is present in only 25% (6 of 24) of DRw6 patients. The results of our analysis indicate that predisposition to PV is conferred by different sequences in DR4 and DRw6 haplotypes. The DR4 susceptibility is highly associated with the Dw10 DR beta I allele, implicating the polymorphic residues in the third hypervariable region. The DRw6 susceptibility is strongly associated with a rare DQ beta allele (DQB1.3). This allele differs from a common DQ beta allele (DQB1.1) only by a valine----aspartic acid substitution at position 57.

Abstract

TCR beta chain gene expression of individual T cell clones that share the same MHC class II restriction and similar fine specificity for the encephalitogenic NH2 terminus of the autoantigen myelin basic protein (MBP) has been examined. TCR V beta expression was examined by FACS analysis with mAbs specific for the V beta 8 subfamily of TCR beta chain genes. 14 of 18 (78%) NH2-terminal MBP-specific clones examined express a member of the TCR V beta 8 subfamily. Southern analysis was used to identify which member(s) of the TCR V beta 8 subfamily is expressed by these clones. Each of four clones examined uses V beta 8.2, though two different V beta 8.2-J beta 2 combinations were identified. Our findings indicate that there is restricted TCR V beta usage in the autoimmune T cell response to the dominant encephalitogenic NH2-terminal epitope of the MBP. The use of an mAb to the antigen-specific TCR in the prevention of T cell-mediated autoimmune disease has been investigated. Our results demonstrate that in vivo administration of a TCR V beta 8-specific mAb prevents induction of autoimmune encephalomyelitis.

Abstract

Pertussis toxin is produced by the causative agent of whooping cough, Bordetella pertussis, and is an adenosine diphosphate (ADP)-ribosyltransferase capable of covalently modifying and thereby inactivating many eukaryotic G proteins involved in cellular metabolism. The toxin is a principal determinant of virulence in whooping cough and is a primary candidate for an acellular pertussis vaccine, yet it is unclear whether the ADP-ribosyltransferase activity is required for both pathogenic and immunoprotective activities. A B. pertussis strain that produced an assembled pertussis holotoxin with only 1 percent of the ADP-ribosyltransferase activity of the native toxin was constructed and was found to be deficient in pathogenic activities associated with B. pertussis including induction of leukocytosis, potentiation of anaphylaxis, and stimulation of histamine sensitivity. Moreover, this mutant strain failed to function as an adjuvant and was less effective in protecting mice from intracerebral challenge infection. These data suggest that the ADP-ribosyltransferase activity is necessary for both pathogenicity and optimum immunoprotection. These findings bear directly on the design of a nontoxic pertussis vaccine.

Abstract

The inheritance of particular alleles of major histocompatibility complex class II genes increases the risk for various human autoimmune diseases; however, only a small percentage of individuals having an allele associated with susceptibility develop disease. The identification of allelic variants more precisely correlated with disease susceptibility would greatly facilitate clinical screening and diagnosis. Oligonucleotide-primed gene amplification in vitro was used to determine the nucleotide sequence of a class II variant found almost exclusively in patients with the autoimmune skin disease pemphigus vulgaris. In addition to clinical implications, the disease-restricted distribution of this variant should provide insight into the molecular mechanisms underlying associations between diseases and HLA-class II genes.

Abstract

Experimental allergic encephalomyelitis (EAE) is an autoimmune disease mediated by CD4+ T cells. Prior studies have established that monoclonal anti-CD4 antibodies can reverse EAE. To determine whether immunoglobulin isotype plays a role in the therapy of EAE with anti-CD4 antibody, an isotype switch variant family of the mouse IgG1 anti-rat CD4 antibody W3/25 was isolated with the fluorescence-activated cell sorter. The IgG1, IgG2b, and IgG2a W3/25 isotype variants all had identical binding capacities for rat CD4+ T cells. Although all three W3/25 isotypes showed some beneficial effects in the amelioration of EAE, the IgG1 and IgG2a W3/25 antibodies were superior to the IgG2b W3/25 in the treatment of EAE. Multiparameter fluorescence-activated cell sorter analysis of T cell subpopulations from treated rats showed that none of the antibodies of the W3/25 isotype switch variant family substantially depleted CD4+ target cells in vivo. These experiments demonstrate that immunoglobulin isotype is important in the monoclonal antibody therapy of autoimmune disease. They indicate that therapy of EAE may be successful without a major depletion of CD4+ lymphocytes. Immunotherapy may be optimized by selecting an appropriate isotype of a monoclonal antibody.

Abstract

Treatment of experimental allergic encephalomyelitis with monoclonal antibodies to products of immune response genes and to surface markers on T cells was reviewed. Both anti Ia therapy and anti T4 therapy can reverse ongoing paralysis, and block subsequent relapses. The appearance of T4 cells and Ia antigens in relapse was demonstrated. The prospects for human therapy with chimeric human-mouse immunoglobulins and isotypic variants was discussed, with particular attention to the immunotherapy of multiple sclerosis.

Abstract

Allele-specific monoclonal anti-I-A antibodies are capable of specifically suppressing the immune response to antigens under the control of the allele towards which the antibody is directed, without suppressing the response to antigens under the control of the alternative allele of the I-A alpha and beta chain genes in an F1 heterozygote. This phenomenon, which has been termed 'allele-specific immunosuppression', is antigen-specific, long-lasting and transferrable with Thy-1-positive spleen cells. This type of immunosuppression has been applied to animal models of autoimmune disease, in both homozygous and heterozygous animal models. Anti-I-A monoclonal antibodies are capable of preventing, suppressing and treating experimental allergic encephalomyelitis (EAE), of partially suppressing experimental autoimmune myasthenia gravis, and of preventing the onset of type I insulin-dependent diabetes in the BB/W diabetic rat. In addition, this type of immunotherapy has succeeded in almost completely suppressing nephritis in NZB X NZW F1 mice, which normally develop severe lupus-like nephritis. Significant toxicity, which may be due to anti-allotype antibodies, anti-idiotype antibodies, or to impurities in the monoclonal antibody preparations, has been encountered in the BB/W diabetic rat. In addition, attempts to extend these observations to EAE in the cynomolgus monkey have encountered significant mortality which appears to be attributable to the monoclonal antibody injections (anti-HLA-DR). The mechanism of this toxicity and means of circumventing it are currently under investigation. These results demonstrate the critical role of I-A molecules in the induction and continuance of the autoimmune process in these experimental animal models.

Abstract

Chronic relapsing paralysis and demyelination within the central nervous system (CNS), features associated with the human disease multiple sclerosis (MS), develop in mice after injection of murine T-cell clones specific for the autoantigen myelin basic protein (MBP). We examined the fine specificity of three independently derived encephalitogenic T-cell clones using synthetic polypeptides derived from portions of the N-terminal sequence of MBP. These clones appear functionally identical; they all respond to an epitope in the N-terminal nine amino acid residues in association with the same class II (I-A) molecules of the major histocompatibility complex (MHC). Both the N-terminal acetyl moiety and the first residue (Ala) are necessary for recognition. Only N-terminal MBP peptides recognized by these clones were found to cause encephalomyelitis (EAE) in vivo. These results show that the N-terminal MBP-specific T lymphocytes that mediate autoimmune encephalomyelitis are a small population with a limited repertoire; they all recognise the same combination of MHC and target.

Abstract

We studied a kindred in which 8 members had the neuroretinopathy of Leber's disease; 14 had a progressive, generalized dystonia attributed to striatal degeneration; and 1 had both disorders. The mode of inheritance was compatible with maternal transmission. This neurologic disorder may be a mitochondrial disease.

Abstract

The neuropathology in two biochemically documented cases of propionic acidemia is presented. While spongiform changes in white matter were seen in the infant who died at 12 days, no such changes were evident in an older patient who died at age 23 months. These findings are compared with other aminoacidemias.

Abstract

A 21-year-old woman had typical clinical and biochemical findings of the cherry-red spot-myoclonus syndrome. She had 20/50 acuity in each eye, flutter-like ocular oscillations, rebound nystagmus, and transient vertical dissociation. Cherry-red maculas and optic atrophy were present. Although electroretinographic signals were normal, visual evoked potentials were almost absent. Levels of neuraminidase were significantly reduced in cultured ebroblasts from the patient and her parents, while lysosomal inclusions probably containing oligosaccharides were found in her conjunctival fibroblasts.